JBL D120 reproductions

[horseshead]

Any one had any experience or luck finding JBL D120 copies? Tone Tubby makes some vintage alnicos and there's Weber's California. What does the E120 sound like as compared to the D120? I have heard that guitarists like Dicky Betts choose them as the best replacement sound for the D120's. And how does the E120 compare to some of these D120 copies or recones?

I have a couple of D120F original baskets (including not only the original spider, but also the original dust cap) reconed with a reproduction of the older, pre-100watt version cone - all paper including a paper surround having a different weight paper cone with a separate cloth surround. The voice coil, like the cone, is also propietary but made to exacting specifications. That is, it is edge wound alluminum on a paper former.

Rick

[edgewound]

Hi Rick...

The E120 is simply the most potent 12" extended range speaker ever made. 103dB sensitivity, 300 watts (150watts in open back) power handling. The ceramic E-series motor has more flux in the gap, 1.35T vs. 1.2T for the alnico D/K series, 103dB vs. 101dB sensitivity....results in 1-2 dB more midband efficiency giving it a little fatter tone overall. Cloth m-roll surround allows for both more low end excursion and less cone break-up, which could be viewed as a plus or minus depending on your preference. I think it makes for a much more durable and versatile speaker than the vintage all paper cone-compliance...especially with todays channel switching, clean to high-gain amps....it goes great with my Rivera Knucklehead 55.

Tha only thing I don't like about it is the added weight('bout 6 pounds) of the ceramic magnet. The E120 is like Godzilla....it really screams when you want it to...or can be velvety smooth too. You tell it what to do and it does it. Yeah....Dickey Betts, Les Paul Standard, Marshall and JBL...unmistakeable combination:) :applaud:

Some have tried to reproduce a JBL D/K/E-120...but they're nowhere close. Eminence makes a terrible attempt at an E-120 clone....total waste of time. A D/K reconed with an E-120 kit makes for more power handling and a bit less cone break-up and increased low end. Sounds just like a K-120 which is alnico.

[horseshead]

First, so that I make sure I understood, did you say that when choosing a recone kit for a D series JBL, the E series recone kit is the closest sounding recone kit to the D series and for example Weber and Orange County recone kits are not as good?

Second, you've told of the difference in sound between the D and the E series, but what of the K?

Look at these D120's. There is a little too much glue around the dust caps to be original cones, no?
Rick

[edgewound]

First, so that I make sure I understood, did you say that when choosing a recone kit for a D series JBL, the E series recone kit is the closest sounding recone kit to the D series and for example Weber and Orange County recone kits are not as good?

I'm saying the E-series kit is what the factory specs for the D/K/E-120, and anything other than that is aftermarket. I have not seen, nor heard in my 18 years reconing, and aftermarket recone job that sounds as good as the factory parts.


Second, you've told of the difference in sound between the D and the E series, but what of the K?


The K sounds like the E with an alnico magnet. A little less sensitive...about 2dB less overall...less midrange in the 250-500 hz range.




Look at these D120's. There is a little too much glue around the dust caps to be original cones, no?
Rick
I can't tell enough detail from your pics about your speakers...other than they look like aftermarket reproductions. Usually the cones are too thick and heavy to sound like the vintage originals, and I haven't seen any aftermarket aluminum wire voicecoils...I've only seen copper. I don't do aftermarket recones on E120's...haven't yet anyway...because the sound isn't worth it.....and my customers know that I will use the parts that sound best. So far, that's the JBL kits.

[horseshead]

I'm saying the E-series kit is what the factory specs for the D/K/E-120, and anything other than that is aftermarket.

But the factory specs for the D cone is the D kit, not the E kit, right? It's just that the D kit is no longer available or let's say almost impossible to find, and the E kit is closer in sound to the D kit than any non-JBL recone kit people are using to recone the JBL D series speaker. Is that what you mean?

The K sounds like the E with an alnico magnet. A little less sensitive...about 2dB less overall...less midrange in the 250-500 hz range.

Sounds like an E series speaker but a little more like a K series speaker? In that case I'm just not clear what the K series sounds like as compared with the D series?



I can't tell enough detail from your pics about your speakers...other than they look like aftermarket reproductions. Usually the cones are too thick and heavy to sound like the vintage originals, and I haven't seen any aftermarket aluminum wire wire voicecoils...I've only seen copper. I don't do aftermarket recones on E120's...haven't yet anyway...because the sound isn't worth it.....and my customers know that I will use the parts that sound best. So far, that's the JBL kits.
That picture was not my speakers. Those speakers were a pair of D120F's that sold on ebay last night. I was wondering if I should go for them but I remembered a post last March a year ago on this forum somebody said from looking at a picture that I posted of my D130F's that one of them looked like was possibly reconed with an original D kit in the JBL factory very early because the glue around the dust cap is a little thicker than the glue of an original cone. I wound up not buying the D120F's last night even though the auction ended with an unbelievable price. Ebay just doesn't have unbelievable prices anymore on JBL D series guitar speakers so that's how you know somethings is probably up with that pair.

I still have only the one pair of vintage all paper cone reproductions to load my newly acquired vintage fender quad reverb. That amp takes four speakers. On top of that, each speaker is supposed to be 16 ohms. My all paper JBL 120's still probably sound better than any non-JBL speaker, for example the four Utah V12PC's that are in there now. Whether I have my JBL's reconed and how they will be reconed will depend on what I try to match them with, the kind of JBL I choose for the other two speakers. From talking to you, I already have decided that if I recone my speakers, I would use the E series kit.

I play all styles but generally gravitate toward quieter things like jazz and international styles of music.

Any ideas about how to load my new amp with JBL's if you were me?

Thanks for your help

[Tom Loizeaux]

With a Fender Quad Reverb being an open back cabinet, I think you could mix differant types of drivers, as long as the effiencies and impedances were close. Flat response, hi-fi, or speaker cabinet loading are not issues here.
Most guitar players like some cone break up and peaky responses, so JBLs may not really give you that sound. Guitar amp speakers are a very subjective area! I use many JBL musical instrument drivers but they are only working in my bass amp cabinets and PA and stage monitor boxes.
The best advice is to try as many combinations as you can.

Tom

[Hamilton]

Peavey claims that their 1203 and 1501DT-4 Black Widow speakers are voiced to the "D" series JBLs. We've done low to moderate level listening comparisons and they do indeed sound extremely close. The 15" being one of the most favorites with pedal steel guitar players.

[Harvey Gerst]

horsehead,

If that were me, I'd load that sucker up with four D123's - my favorite guitar speaker.

[hapy._.face]

horsehead,

If that were me, I'd load that sucker up with four D123's - my favorite guitar speaker.


Yep. I also love the D130..wonder why? Who designed them? :)

The D123 is a heavenly 12. Harvey has stated this before but I think it bears mentioning again- don't clamp them tight to the baffle. Right? I'd like to think I lerned sumpin'.

[spkrman57]

I like to run mine with a single-ended EL84 pentode amp. The little 5 watt output seems to be just right for the 15 watt rated D123!

Ron

[Harvey Gerst]

I like to run mine with a single-ended EL84 pentode amp. The little 5 watt output seems to be just right for the 15 watt rated D123!

RonThe D123 will handle a lot more than 15 watts. It should handle as much as a D110F. It should work fine with a 50 or 60 watt amp, as long as you don't push it really hard.

[horseshead]

horsehead,

If that were me, I'd load that sucker up with four D123's - my favorite guitar speaker.
Why are they your favorite guitar speaker? I was just reading on this forum somebody saying to stay away from them when looking for a d120 replacement.

A fender quad is rated at 100w output (rms?) so wouldn't putting four 16 ohm d123's in it force the amp to put too much voltage on the output tubes or some other part, and blow or at least prematurely age the tubes or other parts?

Can you describe what my reproduction vintage all paper cone compliance d120's sound like compared to the K120's and the d123's?

Rick

[edgewound]

Rick,

It's nearly...no...impossible to describe how your repro D120's sound next to a Factory K120. I can describe the originals though. The K will have a little lower bottom end and slightly less cone breakup than the D120 due to the increased compliance of the suspension. The K will also take nearly double the power due to the higher temp aluminum coil former. I hope that helps. I know it's difficult to translate without actually hearing them.

The D123 will not have the high freq extension of the D120, nor will it have near the sensitivity. The cone is much heavier/ thicker and ribbed.

[Harvey Gerst]

Why are they your favorite guitar speaker? I was just reading on this forum somebody saying to stay away from them when looking for a d120 replacement. I think they sound smoother and warmer than the D120F. They'd be better for blues and jazz, but that's just my opinion. Rock is a different story - there, you need the extra power handling the D120F's provide. But if somebody warned you away from the D123's, perhaps you should take their advice. Maybe they know something about them that I don't.


A fender quad is rated at 100w output (rms?) so wouldn't putting four 16 ohm d123's in it force the amp to put too much voltage on the output tubes or some other part, and blow or at least prematurely age the tubes or other parts? Well splitting the power up among four D123's (wired in series/parallel) would result in about 25 watts max to each speaker. Can't see where that would be much of a problem for the amp or the speakers. How many times have you turned the amp all the way to 10?


Can you describe what my reproduction vintage all paper cone compliance d120's sound like compared to the K120's and the d123's?

Rick I haven't the faintest idea what the hell a "reproduction vintage all paper cone compliance D120" speaker sounds like.

I've heard a lot of D120F original speakers, a lot of D123's, but I've never heard a K120 that I recall.

I've already told you what I would do if it were me making that decision. Sounds like you've already made up your mind about it. Sorry, I didn't mean to hijack your thread; just wanted to offer an alternative solution, based on your style of playing. I'll shut up now.;)

[horseshead]

I think they sound smoother and warmer than the D120F. They'd be better for blues and jazz, but that's just my opinion. Rock is a different story - there, you need the extra power handling the D120F's provide. But if somebody warned you away from the D123's, perhaps you should take their advice. Maybe they know something about them that I don't.

I'm sure whoever wrote it meant the d123's were not for loud music as I recall he mentioned that they were designed for low power home stereos. I can't seem to sift through the many threads on this subject to find it. :biting:


I've already told you what I would do if it were me making that decision. Sounds like you've already made up your mind about it. Sorry, I didn't mean to hijack your thread; just wanted to offer an alternative solution, based on your style of playing. I'll shut up now.;)

Why apologize? I'll just buy the d123 and get back to you how it works out with my stereo guitar setup - dual showman reverb/2xjbl d130f's, and the quad. Thanks for the input. It is greatly appreciated.
Rick (horseshead)

[Harvey Gerst]

I'm sure whoever wrote it meant the d123's were not for loud music as I recall he mentioned that they were designed for low power home stereos. I can't seem to sift through the many threads on this subject to find it.
Actually, Bill Burton designed the D123 primarily to fit inside standard 4" walls, to be used in built-in home systems. It was a radical departure from all the other Jim Lansing speakers at the time. We never considered it as a "low-powered" speaker. That basic 12" design was the foundation for the L100's and the 4310/11/12 studio monitors - all designed for "loud music".


Why apologize? I'll just buy the d123 and get back to you how it works out with my stereo guitar setup - dual showman reverb/2xjbl d130f's, and the quad. Thanks for the input. It is greatly appreciated.
Rick (horseshead)
Well, it kinda drifted from your main question about finding good D120 replacements.

But if it were me, I'd leave the Dual Showman at home, and just bring the quad. It would also be easier to lift.:D

[toddalin]

I have a line on a possible pair of K120's reported to be in good condition (someone is in line infront of me though). Are those of interest to you and if so, how much are you looking to spend?

[horseshead]

I have a line on a possible pair of K120's reported to be in good condition (someone is in line infront of me though). Are those of interest to you and if so, how much are you looking to spend?

If only I knew what the K120's sounded like I'd be able to say. I don't want to sound like the guitarist from the song in that home depot TV commercial that they also play on the phone when you're on hold, so...... no E120's for me I guess. No one yet seems to be able to describe the sound of a K series, only the D versus the E series.

Rick

[edgewound]

If only I knew what the K120's sounded like I'd be able to say. I don't want to sound like the guitarist from the song in that home depot TV commercial that they also play on the phone when you're on hold, so...... no E120's for me I guess. No one yet seems to be able to describe the sound of a K series, only the D versus the E series.

Rick

I described it a few posts ago. You're just gonna have to try them yourself. No amount of description will satisfy your liking them or not. If you don't like them....somebody will.;) :D

[horseshead]

I've already got on that 16 ohm D123 and bought one last night off ebay. I need 3 more and my quad to finnish being checked out which will be in two weeks. I'll hook them up to the quad then and share my findings with you and the group. I've got low power JBL D120's already, as I have said. They are one piece paper, single ring in other words, no separate cloth added (or any other material) for the surround. My reconer said they're what d120's were like originally, back in '57 or '58, and as I've said, they are rated at, like, 20,25 watts, something like that, but they can easily handle 40, even 50 watts. Though, for my taste, they don't sparkle like the later, two piece cone version. They don't have the clarity. They don't stay clean when you play a little loud. On that note, we'll see how I like the D123's.

Rick

[edgewound]

I've already got on that 16 ohm D123 and bought one last night off ebay. I need 3 more and my quad to finnish being checked out which will be in two weeks. I'll hook them up to the quad then and share my findings with you and the group. I've got low power JBL D120's already, as I have said. They are one piece paper, single ring in other words, no separate cloth added (or any other material) for the surround. My reconer said they're what d120's were like originally, back in '57 or '58, and as I've said, they are rated at, like, 20,25 watts, something like that, but they can easily handle 40, even 50 watts. Though, for my taste, they don't sparkle like the later, two piece cone version. They don't have the clarity. They don't stay clean when you play a little loud. On that note, we'll see how I like the D123's.

Rick

Hi Rick,

That's why I suggested the K or E series because they do play cleaner. It'll be interesting to hear your thoughts on the D123. We'll stay tuned.:)

BTW...is your reconer JBL Authorized Service? Can he offer you the factory spec'd recone kit?
If not...that answers other questions already. If it's aftermarket...it's not a JBL.

[horseshead]

Hi Rick,

That's why I suggested the K or E series because they do play cleaner. It'll be interesting to hear your thoughts on the D123. We'll stay tuned.:)

BTW...is your reconer JBL Authorized Service? Can he offer you the factory spec'd recone kit?
If not...that answers other questions already. If it's aftermarket...it's not a JBL.

According to my reconer, whose name btw is Glenn Harrell (Wesley Audio/Viseo, he worked at JBL in the factory and used to do recones with original JBL recone kits a long time ago. He gets his parts from various aftermarket suppliers but the baskets were original from '70's orange JBL D120F's. This is what he recently had to say about how he reconed them.

My speakers have original spider and dust cap, proprietary cone - original weight, paper surround, proprietary voice coil - edgewound aluminum on paper former to exacting specifications.

Rick

[scott fitlin]

According to my reconer, whose name btw is Glenn Harrell (Wesley Audio/Viseo, he worked at JBL in the factory and used to do recones with original JBL recone kits a long time ago. He gets his parts from various aftermarket suppliers but the baskets were original from '70's orange JBL D120F's. This is what he recently had to say about how he reconed them.

My speakers have original spider and dust cap, proprietary cone - original weight, paper surround, proprietary voice coil - edgewound aluminum on paper former to exacting specifications.

RickI dont know! JBL is JBL, and aftermarket just aint JBL!

[horseshead]

I dont know! JBL is JBL, and aftermarket just aint JBL!

I guess it's just too much to ask for four jbl d120 16 ohm speakers. That's what it's come down to.

[Tom Loizeaux]

I guess it's just too much to ask for four jbl d120 16 ohm speakers. That's what it's come down to.

Not at all! Keep an eye out.
These things do come up on eBay. The 16 ohm versions will sell for less then the 8 ohm versions!

Tom

[horseshead]

Not at all! Keep an eye out.
These things do come up on eBay. The 16 ohm versions will sell for less then the 8 ohm versions!

Tom

How do the D131's spec out as compared with the D120's? And the D120F's have the same specs as the D120'?

Rick

[Harvey Gerst]

How do the D131's spec out as compared with the D120's? And the D120F's have the same specs as the D120'?

RickThe D131 is almost identical to the D120F, maybe 1dB more efficient. The surround on the D131 will dry out and crack sooner than the D120F.

[hapy._.face]

...if somebody warned you away from the D123's, perhaps you should take their advice. Maybe they know something about them that I don't.


Yeah, OK. :D

Rick,

Edgewound is right on with the description. I will add that D123's tend to give me more feedback. No not the high pitched kind- but they feel more...intimate (?). Personally, I like a little break up- I'm not looking for high fidelity when I play guitar. I don't think your 100W bruiser will hurt the 123's at ALL. Even so- no matter what kind of guitar style you're in to- blowing tubes and damaging stuff is just part of the fun. D123's offer a fun ride. For me- they hide fingerstyle artifacts, they have a pleasing tonality, and sound excellent when driven to the brink. I even had D130's and D123's in a pair of JBL Baron home speakers and listening to Hendrix through them was like having your head in his amp. Nice!

Oh, and 16 ohm = 8 ohm. I've never seen a pair test higher than a 7.3 (Can anyone else substantiate that?)

Let us know what your findings are!

[horseshead]

[quote=hapy._.face]Yeah, OK. :D


Oh, and 16 ohm = 8 ohm. I've never seen a pair test higher than a 7.3 (Can anyone else substantiate that?)


The output transformer/tubes of a fender quad/dual showman/twin are all wired for 4 ohms load total. It doesn't care what speaker combination. If you put too much resistance (load) or too little it can kill the tubes too soon. I find it hard to believe that a company like JBL with such an unapproachable reputation for perfection of production and engineering design would just say, yeah, whatever, we'll just wing the impedience tolerances.

Rick

[edgewound]

DCR of C8RE120 is 6.3 ohms +/-10%
DCR of C16RE120 is 13 ohms +/-10%

I do believe that JBL tried to rate the impedance of the drivers' operating frequency range, especially on HF drivers...not just DCR.

[Harvey Gerst]

[quote=hapy._.face]Yeah, OK. :D


Oh, and 16 ohm = 8 ohm. I've never seen a pair test higher than a 7.3 (Can anyone else substantiate that?)


The output transformer/tubes of a fender quad/dual showman/twin are all wired for 4 ohms load total. It doesn't care what speaker combination. If you put too much resistance (load) or too little it can kill the tubes too soon. I find it hard to believe that a company like JBL with such an unapproachable reputation for perfection of production and engineering design would just say, yeah, whatever, we'll just wing the impedance tolerances.

Rick Sorry Rick, but he's right. While we did maintain pretty tight tolerances, our 16 ohm speakers were really about 8 ohms and our 32 ohm speakers were closer to 16 ohm. Why? To make them a little louder. Remember, these were tube amps we were feeding. If you have a big hunk of iron for a transformer, tube amps are a little less fussy about lower impedance loads. Later, JBL just added "8 - 16 Ohms" on the label.

We never said, "whatever". That expression didn't appear until many years later.

[toddalin]

If only I knew what the K120's sounded like I'd be able to say. I don't want to sound like the guitarist from the song in that home depot TV commercial that they also play on the phone when you're on hold, so...... no E120's for me I guess. No one yet seems to be able to describe the sound of a K series, only the D versus the E series.

Rick

OK, I let them go. Too bad too. At $90/pr, price was pretty good.

[Don McRitchie]

Back to the original question, Standel Musical Instrument Amplifiers was making copies of JBL's Alnico "D" series drivers for a time. I couldn't find reference to this on their current web site, but it may be worth a call to see in they are still in production.

http://www.standelamps.com/

[horseshead]

[quote=horseshead] Sorry Rick, but he's right. While we did maintain pretty tight tolerances, our 16 ohm speakers were really about 8 ohms and our 32 ohm speakers were closer to 16 ohm. Why? To make them a little louder. Remember, these were tube amps we were feeding. If you have a big hunk of iron for a transformer, tube amps are a little less fussy about lower impedance loads. Later, JBL just added "8 - 16 Ohms" on the label.

We never said, "whatever". That expression didn't appear until many years later.

Should I keep all four speakers the same impedence rating, either all four rated at 16 ohms or all four rated at 8 ohms? When fender quad reverb customers wanted to special order JBL's what were put in there, 8 ohm or 16 ohm?

I've been wondering what were some home stereo models and brands that were created for the mass market and typically sold with JBL D120's,123's or 131's?

Rick

[horseshead]

Back to the original question, Standel Musical Instrument Amplifiers was making copies of JBL's Alnico "D" series drivers for a time. I couldn't find reference to this on their current web site, but it may be worth a call to see in they are still in production.

http://www.standelamps.com/

Thanks, I will call them.

Rick

[Harvey Gerst]

Should I keep all four speakers the same impedence rating, either all four rated at 16 ohms or all four rated at 8 ohms? When fender quad reverb customers wanted to special order JBL's what were put in there, 8 ohm or 16 ohm?

I've been wondering what were some home stereo models and brands that were created for the mass market and typically sold with JBL D120's,123's or 131's?

RickI'd keep them all the same. Most of the old fender transformers actually had multiple output taps that were set at the factory to accomodate different loads. If you look inside the Fender head, there should be some unused wires coming out of the output side of the transformer that offer other impedances.

There were never any home systems that used a D120; that was strictly a musical instrument speaker. D131's and D123's were often paired with 075's and even 175DLH's. The C39 cabinet could handle four D123's and an 075.

[horseshead]

OK, I let them go. Too bad too. At $90/pr, price was pretty good.

I am intested in the K120's. It just took me a week to realize this because it can get a little confusing reading different opinions from different people posting here, but I have decided that the best way for me or anyone to find the model JBL that I/they like the best is to try the different models.
Rick

[horseshead]

There were never any home systems that used a D120; that was strictly a musical instrument speaker. D131's and D123's were often paired with 075's and even 175DLH's. The C39 cabinet could handle four D123's and an 075.[/quote]

If not home systems, what were these, strictly JBL stereo systems, and strictly their professional line?

Rick

[horseshead]

DCR of C8RE120 is 6.3 ohms +/-10%
DCR of C16RE120 is 13 ohms +/-10%

I do believe that JBL tried to rate the impedance of the drivers' operating frequency range, especially on HF drivers...not just DCR.

What does the acronym DCR stand for? And thanks edgewood, I did find description of the sound of K's a few posts back. :barf:

Rick

[horseshead]

I have a line on a possible pair of K120's reported to be in good condition (someone is in line infront of me though). Are those of interest to you and if so, how much are you looking to spend?

Are those the ones you already let go for $90? If not, then I would need to know if they are original cones before offering a price.

Rick

[Harvey Gerst]

There were never any home systems that used a D120; that was strictly a musical instrument speaker. D131's and D123's were often paired with 075's and even 175DLH's. The C39 cabinet could handle four D123's and an 075.
If not home systems, what were these, strictly JBL stereo systems, and strictly their professional line?

Rick
Sorry if it was a confusing answer. Lemme see if I can clear it up. The 15" D130 and the 12" D131 were designed as hi-fi speakers, period. At one point, Bob Crooks of Standel and Leo Fender started selling them as options in their guitar amps. The D123 was also a hi-fi speaker and was never used as a guitar amp speaker by any of the manufacturers.

From the large number of repairs we/I/JBL was getting back from these amp manufacturers, two things became apparent to me:

1. These guys were selling the shit out of these speakers, so there was a big market out there.
2. The standard D130 and D131 wouldn't hold up long-term as an OEM product for musical instument applications.

I approached Bill Thomas to let me design some speakers for this market that would:

1. work better without blowing up (due to mismounting, and surrounds
drying out and cracking),
2. increase sales by expanding the line to include a 10" speaker and a 15"
bass speaker.,
3. use existing JBL parts to reduce development and manufacturing costs.

Bill agreed, and I came up with the D110F, D120F, D130F, and the D140F.

While I would have liked to include the lower powered D123 in the MI line (for use in multiple 12" speaker systems), I decided that the popularity and power handling of the already well known D131 would probably give the D123 limited appeal. The D123's sound great in a Twin, for example, as long as you don't push them really hard. I had a D123 in an Ampeg Portaflex, and it was a wonderful sound.

The D110F in fact uses the D123 motor (magnet assembly and 3" voice coil).

So, the C39 with four D123's and an 075 was strictly a home hi-fi speaker, while the D130's and D131's did see early MI use, until the introduction of the "F" series.

That clear things up?

[horseshead]

The D131 is almost identical to the D120F, maybe 1dB more efficient. The surround on the D131 will dry out and crack sooner than the D120F.

I remember something you wrote here a long time ago about one of your contributions in the development of the D120/130 and how adding some goop to the surround of a D131 prevented the surround from drying out and cracking too soon and it also may have helped something else.

Which speaker is more efficient - the D120 or the D131? I guess Do you think mixing 120's and 131's that you would hear the loss of volume in - I don't know - which speaker is less efficient? see question above

Rick

[Harvey Gerst]

I remember something you wrote here a long time ago about one of your contributions in the development of the D120/130 and how adding some goop to the surround of a D131 prevented the surround from drying out and cracking too soon and it also may have helped something else.

Which speaker is more efficient - the D120 or the D131? I guess Do you think mixing 120's and 131's that you would hear the loss of volume in - I don't know - which speaker is less efficient? see question above

Rick
The D131 is slightly more efficient than the D120F - because I opened the gap slightly on the D120F to prevent the voice coil from rubbing and burning out. The difference in efficiency between the two models is negligable. The D120F will keep working for a lot longer than the D131, under harsher conditions.

[johnaec]

What does the acronym DCR stand for?As far as I know, it stands for Direct Coil Resistance or Direct Current Resistance. It's the measured value in ohms you'll get when measuring across the loudspeaker leads when nothing, (crossover, other wires, amp, etc.), is conected to it. Manufacturers typically publish "nominal" impedance, which is more of an average value over a range of frequencies, since it can vary greatly by frequency. DCR values are good for verifying normal continuity, and for comparing speakers when trying to closely match pairs. Someone else can probably give a more definitive definition - mine's the "Cliff Note's" version... ;)

John

[Harvey Gerst]

What does the acronym DCR stand for?

Rick
DCR means DC resistance; the measurement of the voice coil resistance at rest.

When the voice coil starts moving to an AC music signal, the measurement varies with frequency (and a lot of other factors), and that's called "impedance". Speaker impedance is usually measured at around 400 Hz, but impedance can vary wildly at other frequencies. DCR is usually about 70% of the specified impedance.

[Harvey Gerst]

As far as I know, it stands for Direct Coil Resistance or Direct Current Resistance. ;)

John
That's probably a "righter" definition than mine.

[horseshead]

From the large number of repairs we/I/JBL was getting back from these amp manufacturers, two things became apparent to me:


2. The standard D130 and D131 wouldn't hold up long-term as an OEM product for musical instument applications.

I approached Bill Thomas to let me design some speakers for this market that would:

1. work better without blowing up (due to mismounting, and surrounds
drying out and cracking),


Bill agreed, and I came up with the D110F, D120F, D130F, and the D140F.

While I would have liked to include the lower powered D123 in the MI line (for use in multiple 12" speaker systems), I decided that the popularity and power handling of the already well known D131 would probably give the D123 limited appeal. The D123's sound great in a Twin, for example, as long as you don't push them really hard. I had a D123 in an Ampeg Portaflex, and it was a wonderful sound.

The D110F in fact uses the D123 motor (magnet assembly and 3" voice coil).

So, the C39 with four D123's and an 075 was strictly a home hi-fi speaker, while the D130's and D131's did see early MI use, until the introduction of the "F" series.

That clear things up?[/quote]

Yes, mostly. Guitar amplifier speaker longevity doesn't appear to be something that I, for the most part, with my low volume and light touch type of playing/music would have to worry about.
It sounds to me that when you were saying that longevity of the D130 and D131 was a problem in musical instrument applications, you were refering to rock players and hacks. (not to say they're the same, I'm no snob nor am I a stranger to rock and a physically intense style of playing) they just happen to share a preference for loud volume and a heavy touch.
Therefore, the D131's might be something that I would like to buy as one of the possible varieties of JBL 12's for my guitar amp. But I'm still not sure which stereo systems came with the D131's - JBL stereo systems? Which ones?
Rick

[Harvey Gerst]

That clear things up?Yes, mostly. Guitar amplifier speaker longevity doesn't appear to be something that I, for the most part, with my low volume and light touch type of playing/music would have to worry about.
It sounds to me that when you were saying that longevity of the D130 and D131 was a problem in musical instrument applications, you were refering to rock players and hacks. (not to say they're the same, I'm no snob nor am I a stranger to rock and a physically intense style of playing) they just happen to share a preference for loud volume and a heavy touch.
Therefore, the D131's might be something that I would like to buy as one of the possible varieties of JBL 12's for my guitar amp. But I'm still not sure which stereo systems came with the D131's - JBL stereo systems? Which ones?
Rick The original D130's and D131's had two basic problems:
1. The speaker surrounds dried out, got brittle, and cracked.
2. The ham-fisted idiot installers at Fender used power tools to tighten down the speakers, warping the speaker frame, which wound up shorting out the voice coils. I talked to Dick Stout and Forrest White at Fender many times about this. My explanations of how to mount the speakers correctly were ignored.

If you installed the D131's correctly, and don't expose them to extreme temperature changes, the D131's should work fine. Leaving the speakers in a hot car for several hours, or playing outdoors a lot will wreck the surrounds.

As far as home hi-fi's that used the D131, it was usually used in a small system paired with the D175DLH, and later with the 075. The D131 was not a particularly popular speaker. It was basically just a D130 on a 12" frame, for people that wanted the D130 sound, but didn't have the room for a 15" speaker. The JBL catalogs from the 60's are on line here and show which JBL home hi-fi systems were available with the D131's.

As far as a "light touch and low volume", that's exactly why I recommended the D123's as the best 12" speaker choice for your playing.

[toddalin]

Are those the ones you already let go for $90? If not, then I would need to know if they are original cones before offering a price.

Rick

Gone. You snooze, you loose.

[horseshead]

The D131 is slightly more efficient than the D120F - because I opened the gap slightly on the D120F to prevent the voice coil from rubbing and burning out. The difference in efficiency between the two models is negligable. The D120F will keep working for a lot longer than the D131, under harsher conditions.

Thanks Harvey for taking the time to share your experience and knowledge.
Some speakers are marked D120 and some speakers are marked D120F. Is there any difference in the speaker itself? I've read your posts explaining the difference between the D130 and the D130F.

Rick

[Harvey Gerst]

Thanks Harvey for taking the time to share your experience and knowledge.
Some speakers are marked D120 and some speakers are marked D120F. Is there any difference in the speaker itself? I've read your posts explaining the difference between the D130 and the D130F.

Rick
Shortly after we introduced the MI line of speakers, Fender agreed to distribute these JBL MI speakers to musical instrument dealers since they already had most of the MI dealers in the country. (We only sold to hi-fi stores.) I don't remember changing the name of the D120 to the D120F.

(My recollection is that there was never a D120; it was always called the D120F. But enough people have told me that they've seen speakers marked D120 to make me believe it.)

I believe the first D120's had the "F" added as a punchmark; later, the F was printed directly on the foilcal. But, it was a very long time ago, so my memory may not be accurate.


Getting old really sucks!

[Rudy Kleimann]

I have an original pair of JBL 2130's which, according to the alpha-numeric model number listing descriptions is the professional series model number equivalent to a D120. If your memory is right, would this also mean the same as D120F?

My 2130's were used in a pair of '70's vintage custom-made stage floor monitors with the 077 "bullet" tweeter. Cabinet was well-made, and the crossover components were top-notch. The drivers are in good condition, just dusty, dirty, and minor oxidation of the aluminum dust cap and the bullet tweeter horns. No liquid damage. They play fine. Consecutive serial numbers on the drivers :D.

Story has it that these stage monitors and the road case they are in were part of Z*Z*TOP's touring system that was stolen after a concert in Phoenix, AZ in the '70's. A friend of mine was in a band during his College days in Phoenix and bought them a couple days after the theft incident. He never knew the origin of them, but after hearing of the theft, figured it out. Research I have done on the story and the cabinets themselves seems to bear this out as fact. Interesting trivia...

Harvey, my question has always been what to do with the woofers? How well would they perform as guitar speakers for studio use or occasional gigging. I have a vintage fender Bassman amp that works, but no guitar cabinet for the 2130's. Building one would be no problem for me though.

I'm reasonably certain that the 2130's would never be damaged by my Bassman, but how much "guitar playin' abuse" tube power (rated amplifier power in watts of a tube head):blink: do you think these 2130's would tolerate?

Lastly, I'm interested to know anything more about the "other taps" of Fender amp output transformers. How could I identify these? would a DCR check from a common lead to the other taps accurately ID the other taps re: other output impedances compared to the DCR of the known one currently in use in my amp?

[Harvey Gerst]

I have an original pair of JBL 2130's which, according to the alpha-numeric model number listing descriptions is the professional series model number equivalent to a D120. If your memory is right, would this also mean the same as D120F?

My 2130's were used in a pair of '70's vintage custom-made stage floor monitors with the 077 "bullet" tweeter. Cabinet was well-made, and the crossover components were top-notch. The drivers are in good condition, just dusty, dirty, and minor oxidation of the aluminum dust cap and the bullet tweeter horns. No liquid damage. They play fine. Consecutive serial numbers on the drivers :D.

Story has it that these stage monitors and the road case they are in were part of Z*Z*TOP's touring system that was stolen after a concert in Phoenix, AZ in the '70's. A friend of mine was in a band during his College days in Phoenix and bought them a couple days after the theft incident. He never knew the origin of them, but after hearing of the theft, figured it out. Research I have done on the story and the cabinets themselves seems to bear this out as fact. Interesting trivia...

Harvey, my question has always been what to do with the woofers? How well would they perform as guitar speakers for studio use or occasional gigging. I have a vintage fender Bassman amp that works, but no guitar cabinet for the 2130's. Building one would be no problem for me though.

I'm reasonably certain that the 2130's would never be damaged by my Bassman, but how much "guitar playin' abuse" tube power (rated amplifier power in watts of a tube head):blink: do you think these 2130's would tolerate?

Lastly, I'm interested to know anything more about the "other taps" of Fender amp output transformers. How could I identify these? would a DCR check from a common lead to the other taps accurately ID the other taps re: other output impedances compared to the DCR of the known one currently in use in my amp?
If it's the same as a D120, it should be the same as a D120F. It should handle the output of a Fender Bassman. Simple test: Try it. Keep turning it up till it sounds like it's starting to strain, then stop. I don't know anything about the 2130's so I can't be of much help.

As I recall, the unused taps on a Fender output transformer are just sitting there. I'd call Fender and ask for the output transformer color codes. DCR measurements would be pretty damn low so, knowing for sure would be better.

[moldyoldy]

........Lastly, I'm interested to know anything more about the "other taps" of Fender amp output transformers. How could I identify these? would a DCR check from a common lead to the other taps accurately ID the other taps re: other output impedances compared to the DCR of the known one currently in use in my amp?

Just in case you've not found it, The Fender Amp Field Guide may have the color code for your OPT (and a wealth of other Fender info);

http://www.ampwares.com/ffg/

IIRC, some models even had balanced output taps.

[horseshead]

Just in case you've not found it, The Fender Amp Field Guide may have the color code for your OPT (and a wealth of other Fender info);

http://www.ampwares.com/ffg/

IIRC, some models even had balanced output taps.

My amplifier tech said that in my fender quad reverb, for example, it is possible to connect either two speakers or four speakers - as long as the total impedence of the speakers equals 4 ohms in the case of my amp's output transformer requirement, or whatever the impedence in ohms of your amp's output transformer requires. As Harvey also said, make sure
all your speakers are rated the same impedence; for example, either each speaker rated at 8 ohms or each speaker rated at 16 ohms, etc.
Rick

[Rudy Kleimann]

Just in case you've not found it, The Fender Amp Field Guide may have the color code for your OPT (and a wealth of other Fender info);

http://www.ampwares.com/ffg/

IIRC, some models even had balanced output taps.

Thanks for the link. I'll check it out.

I've been told that the Bassman is an old favorite for lead guitar players. Brian Setzer's Sound was one example. I look at it as a modest-power vintage Fender tube amp to add to the arsenal. Modest power keeps the volume on stage (or studio) to a more manageable level- an important plus in my mind as a sound engineer.

What do you mean by 'balanced'? A center-tapped output? :confused:

I'm no tube guitar amp wizard, but AFAIK the only thing that would make a transformers' output unbalanced would be to ground one lead of the output. I have always understood that the lead marked "common" simply meant that it was the lead attached to the beginning of the output windings, with the other impedance taps being more or less number of turns in the windings from the "common" end.

The only thing I can think to do with a center-tapped output would be to attach the center-tap to the mid-point between two speakers connected in series to the "balanced" outputs. Perhaps this would provide better damping? Just a guess...:dont-know

Always interested to learn something new...:hmm:

[moldyoldy]

No, I didn't mean center-tapped secondaries, just 'floating' (ungrounded) secondaries. Only mentioned it so you'd take notice when studying the schematic. Ungrounded secondaries should be kept ungrounded. If you were doing a custom job, and installed a grounded-shield TS jack for speaker outputs on the chassis, you could get in trouble.

(Added edit) More to the point. Your understanding is correct that unbalanced outputs (in this app) have one end of the secondary coil (labeled 'common') connected to ground, and the remaining taps are of varying turns from common, and all are far beyond center. Most tube guitar amps ARE 'unbalanced' as described, so I thought the mention that a few old Fenders were 'non-standard', in that they were balanced (ungrounded) might be important to mention if you're gonna be rewiring the OPT. Since there's no other channel to reference phase with, that issue's moot here (with the exception of effects on acoustic feedback). Tube amps mostly have unbalaced speaker outputs more for safety (grid HV on the primary) than for signal.

I've never seen a center-tapped secondary in a guitar amp OPT. It would take some creative winding to allow one to work as you described with two speakers. Since tube amps are impedance-matching devices, damping is strongly influenced by the driven impedance (speaker), and the JBLs mentioned (as well as Altec 417s and Jensen P12Ns) are a wonderful match, some feel, made in heaven. (End of added edit)

Yeah, the old Bassmans are a fave of mine as well. The low to medium powered old Fenders (mainly the 6V6 ones) are often too weak for stand-alones for gigging, but they can be cranked into clipping while still at modest levels, and mic'd to get any output level you desire. Makes them really more versatile than the big boys, where you're making ears bleed just to let your amp "sing" a little. Just leave 'em on 10 and control your tone at the guitar.:rockon1:

[Tom Loizeaux]

...Yeah, the old Bassmans are a fave of mine as well. The low to medium powered old models are often too weak for stand-alones for gigging, but they can be cranked into clipping while still at modest levels, and mic'd to get any output level you desire. Makes them really more versatile than the big boys. Just leave 'em on 10 and control your tone at the guitar.:rockon1:

I don't know about being too weak. My '62 blonde Bassman holds it's own in a variety of band set-ups. (Yeah, I play it on 8 to 10 in those situations)
Sure, 100 watt Marshalls can cover me up, but I don't play in "stupid loud" sessions anymore.

Tom

[moldyoldy]

I don't know about being too weak. My '62 blonde Bassman holds it's own in a variety of band set-ups. (Yeah, I play it on 8 to 10 in those situations)
Sure, 100 watt Marshalls can cover me up, but I don't play in "stupid loud" sessions anymore.

Tom

OOHHH YEAH! '62 Blonde! Best of the Best!

I should've elaborated, didn't mean to include the Bassman in my later reference, which was targeted at the smaller 6V6 models. Most of the 6L6 models are sufficient for small clubs by themselves. (I edited my previous post to clarify).

[Rudy Kleimann]

I appreciate the info. As I said I'm a Sound Man, equipment repairman, and a horn player (Commercial Electrical construction is my day job). Guitar amps and cabinet setup and tweaking is not my strong suit. But I know how to work on them, and a good speaker cabinet will be a breeze for me to build.

I don't know too much about my Bassman except that it is a vintage model, the high-gain input doesn't work right, and it's not a blond. But it does have the tube complement label inside it, so I should be able to ID it.

I look forward to hooking up the two 2130's in parallel to the 4ohm tap set on the XFMR, and inviting a couple of good guitar playin' friends over to put it through its moves. Time to dig it out of the shed, do my homework, and get to work. Soon as I get the 100 other projects caught up...:D

One thing I HATE:
Young kids (or old kids for that matter) on stage with 100 watt Marshall amps and Marshall 4x12 cabinets screaming at the one part of the audience the cabinet happens to be pointing straight at. A Mix Engineer's nemesis, to say the least... :banghead:

I've done club gigs with guys like this that were so freakin' overpowering loud that the rest of the band (heavily mic'd drums, D.I.'d Keyboards, and DI'd Bass, 4 vocals) playing through a pair of JBL SR4733X (2-2226H's and a 2447J on a 2381 horn) powered by a QSC MX3000a (rated at 1250WPC@4ohms into each cab) or a pair of bridged Mackie 1400's could barely keep pace with the guitar amp. And the people in the audience up front could hardly stand it. I ran it from the back of the club on a 100ft. snake, and my ears were pretty tired by the end of the night. No amount of reasoning could get the guy to turn it down.

Next gig, I convinced him to turn the cabinet sideways on stage, hoping his fellow musicians might get tired of it and rein him in, but they just loved it. Even turned him up in the monitors hoping they would get the message, but they got pissed at me instead. "I just don't get the tone I like if I don't play loud..." :biting:

Smaller amps help two ways: lower volume, and still get that crunch and overdrive saturation tubes are good for. I can mic it if I need to.


Any suggestions on cabinet design? Open back, 1/2 open, or sealed? What cabinet volume? Insulation or no?

[moldyoldy]

Your layout tag will have a model, such as 5E3 (sounds like a tube #, but it's not), which is the number to use to select a schematic.

If it's been in the shed or otherwise unused for a couple years or more, I'd recommend a slow, Variac start-up to reform the electrolytic caps.

For your 100W Man, you've got 2 options; find out if he's using a master volume model, and, if so, show him how to get the tone he wants at the pre, and turn the master down, or.....if all else fails, insert a quality AC controller in his line V. supply, and brown him down to 90-100VAC or so..... won't hurt a thing. The rest of the band will likely cooperate, too.......;) (Edit: my latter suggestion was a poor attempt at humor, do NOT mess with a musicians' power source!)

For the cab, why not clone the real thing? Dimensions, pictures, schematics, and details for most models are at the site I linked to earlier. Naturally, they also sell tolex, cloth, pts, etc.

[horseshead]

Harvey - when purchasing JBL's online, my lack of experience and knowledge, especially not physically being there to check out the speaker, I am at a loss to know what to do about it. What would be your recommendation regarding such defects as a pinhole or small tear in the surround and/or cone edge? What would be compromised by buying a speaker such as that? Rick

[edgewound]

One thing I HATE:
Young kids (or old kids for that matter) on stage with 100 watt Marshall amps and Marshall 4x12 cabinets screaming at the one part of the audience the cabinet happens to be pointing straight at. A Mix Engineer's nemesis, to say the least... :banghead:

I've done club gigs with guys like this that were so freakin' overpowering loud that the rest of the band (heavily mic'd drums, D.I.'d Keyboards, and DI'd Bass, 4 vocals) playing through a pair of JBL SR4733X (2-2226H's and a 2447J on a 2381 horn) powered by a QSC MX3000a (rated at 1250WPC@4ohms into each cab) or a pair of bridged Mackie 1400's could barely keep pace with the guitar amp. And the people in the audience up front could hardly stand it. I ran it from the back of the club on a 100ft. snake, and my ears were pretty tired by the end of the night. No amount of reasoning could get the guy to turn it down.

Next gig, I convinced him to turn the cabinet sideways on stage, hoping his fellow musicians might get tired of it and rein him in, but they just loved it. Even turned him up in the monitors hoping they would get the message, but they got pissed at me instead. "I just don't get the tone I like if I don't play loud..." :biting:

Smaller amps help two ways: lower volume, and still get that crunch and overdrive saturation tubes are good for. I can mic it if I need to.


Any suggestions on cabinet design? Open back, 1/2 open, or sealed? What cabinet volume? Insulation or no?

We've discussed this before about stage volume and it's OT in this thread, but here ya go.

Plexiglass in front of the speaker cabinet will appease everyone. Then mic it to taste for front-of-house. It's a cheap alternative before trying to fool anyone electrically....which could be called vandalism.

[moldyoldy]

Good points Edge. To clarify my brown power suggestion (plus wink) for others, it was a joke that I thought Rudy, as an electrician, would get a grin at, and I hadn't considered that some might take it seriously. I'll add an edit to clarify the post. Enough OT for me.

[Hamilton]

One thing I HATE:
Young kids (or old kids for that matter) on stage with 100 watt Marshall amps and Marshall 4x12 cabinets screaming at the one part of the audience the cabinet happens to be pointing straight at... :banghead:
Do guys really do that?

[edgewound]

Good points Edge. To clarify my brown power suggestion (plus wink) for others, it was a joke that I thought Rudy, as an electrician, would get a grin at, and I hadn't considered that some might take it seriously. I'll add an edit to clarify the post. Enough OT for me.

I knew a few guys that would use a variac with their Marshalls and turn down the AC to about 90 volts to get a cool tone. Don't know how that affects the amp, though....effects work like crap and so do PA amps.

Eddie Van Halen went the other way and cranked his AC to 140 volts to get that gnarly tone on his early records. Kinda hard on the tubes...and everything else for that matter.

[moldyoldy]

Yeah, I've left several tube amps on the bench at 90VAC on the Variac overnight with no apparent ill effects, and many will actually play down to 60VAC. Still, it would be a dirty trick to play on anyone, even though it might help prepare them for the inevitable screwin's they'll get at the hands of producers and record labels......:banghead:

Ooops! said I was done OT...:blah:

[spkrman57]

Yeah, I've left several tube amps on the bench at 90VAC on the Variac overnight with no apparent ill effects, and many will actually play down to 60VAC.


With 90 volts to the amp the rectifier(usually 5U4 or 5AR4) would be running at less than the 5 volts on filament and probably less than the required current to properly cause the electrons to leave the cathode.

While it will work(not blow up or shut down), I would say it will probably reduce the lifespan of the tubes!

Ron:blink:

[Rudy Kleimann]

Do guys really do that?


ROFLMAO!:rotfl: :rotfl: :rotfl: :rotfl: :rotfl:

Hamilton, you and your Avatar are living proof!

It's fine in the right Venue, but a 100-200 seat club is not it.

I'm as guilty as the next guy, but I use a Trumpet to do it instead of a guitar and amp. I don't think it ever offended ANYONE :no:

I could be wrong, though:p

[toddalin]

I knew a few guys that would use a variac with their Marshalls and turn down the AC to about 90 volts to get a cool tone. Don't know how that affects the amp, though....effects work like crap and so do PA amps.

Eddie Van Halen went the other way and cranked his AC to 140 volts to get that gnarly tone on his early records. Kinda hard on the tubes...and everything else for that matter.

Ever try to play a Hammond on a LARGE portable generator!:D The Hammond works by locking onto the 60 cycle a/c and in this case it wouldn't! The tone wheels were all over the place!:biting: Neigher my Moog nor my Electrocomp synthesizers would hold tone either.:(

Also burned out all of our Acoustic amp power transistors (Acoustic Model 270).

[Rudy Kleimann]

Your layout tag will have a model, such as 5E3 (sounds like a tube #, but it's not), which is the number to use to select a schematic.

If it's been in the shed or otherwise unused for a couple years or more, I'd recommend a slow, Variac start-up to reform the electrolytic caps.

For your 100W Man, you've got 2 options; find out if he's using a master volume model, and, if so, show him how to get the tone he wants at the pre, and turn the master down, or.....if all else fails, insert a quality AC controller in his line V. supply, and brown him down to 90-100VAC or so..... won't hurt a thing. The rest of the band will likely cooperate, too.......;) (Edit: my latter suggestion was a poor attempt at humor, do NOT mess with a musicians' power source!)

For the cab, why not clone the real thing? Dimensions, pictures, schematics, and details for most models are at the site I linked to earlier. Naturally, they also sell tolex, cloth, pts, etc.

Thanks for all the tips, Moldy! I'll check out the site, armed with your ID information. The cab clone sounds like the right plan. Lord knows I can find enough ebayers selling the TOLEX and grille cloth. Penn Fab makes almost everybody's (including JBL's) metal or plastic cabinet and road case hdwe, and one of their three worldwide offices is only a few miles away from me.

:idea: Anybody need any hardware for their JBL or any other Pro cabs or road cases?
Just drop me a line... everything except the "JBL" logo, that is. Corners, handles, butterfly catches, input connection plates, wheels, grilles, carpet, fans, rack rails, drawers, faceplates, you name it.

My Bassman has been used only 3-4 times in the four years I've owned it and I have no history on it, so the variac is a good idea for when I get into reviving it.

Got to admit though, you had me going on the 90V AC to the Marshal JCMxxxx 100W head thing! I'm glad you included the reality check... I'm sure it would bring about some distortion at a much earlier point, but may have been disastrous!

Edgewound: We tried the plexiglass trick with an SM57 (his choice) in front of it, but had the most awful feedback problem that we took it down after the 2nd set and never tried it again. No matter, I don't do sound for that Band anymore. He's the only one I ever had a bad problem with anyway. Garage bands, they come and they go...

[Hamilton]

I agree with Moldy, running a Marshall down to 90-100 vac won't damage a thing, but as spkrman57 says, that might cause some cathode stripping....maybe. I sure wouldn't worry about it, there's guys out there that play that way and nothing goes up in smoke. If anything, the amp runs cooler.

The best and most logical way to calm one of those brutes down is with an attenutor, but they're near $300 :

http://media.zzounds.com/media/brand,zzounds/fit,325by400/quality,85/HotPlate-ebd5ea141f5078d95e08490e97cc7a96.jpg

[Rudy Kleimann]

Looks like the "Power Soak" from the late '70's invented by Tom Scholz of the rock band "Boston" fame. Nothing more than load resistors with high power capacity: Use most of the amp's output to heat up the load resistors and divert the remaining available power to the actual speaker(s).

If you want cone breakup for micing , use the power soak with 1 or 2 drivers instead of 4 or 8. Make those tubes cry or scream at modest spl's.

[Hamilton]

Rudy, your night to mix, would this make you a little nervous?

[Rudy Kleimann]

NICE!

Your rig? (or rather, rigs?) That's for the medium to large nightclub Venues, right? :nutz:

No problem, although I'd need a little more $$$ for this one, since it's evident that I'll have to bring my own AC Distribution panel and more FOH and monitor gear to keep up.:D Does the place have a 200 Amp D/S I can hook into? Is the building structurally sound?

Looking at the picture, the Chet Atkins Fender Acoustic Electric looks a little out of place:p .

Nice drum kit too. Are those SM 81's overhead?

[Hamilton]

I thought you might get a kick out of that.

I'm not sure who's backline that is, but someone said it might belong to this guy. :D

http://www.yngwie.org/images/Hdr3b2.jpg

[Rudy Kleimann]

Yeah, that was pretty good:p

I like the ropelights stretched around inside the back of his PA amp rack. I always have some kind of lights in the back of mine for those little "Awww-shit!!!"-s or bright ideas that seem to occasionally happen during a show. Nice soft light, but enough to get you through it without too much distraction for the audience.

I went to the www.ampwares.com/ffg (http://www.ampwares.com/ffg) site to check out ideas for my dual D120 speaker cab clone project like someone else here suggested. Turns out I had been there before. Found what looks like my Fender Bassman amp (IIRC). Probably a Blackface '64-67 model. I need to bring the amp home to be sure.

However, I couldn't find a way to search for speaker cabs by driver mfg or model. The speakers I did check out didn't have the speaker complement I am looking for.

I want to make a 2x12 cab for my JBL Professional Series 2130's (pro version of the D120). Harvey Gerst has all but guaranteed these are identical to the D120F's. I want use them for lead guitar and drive the cabinet with the Bassman Amp.

A clone of a Vintage Fender cabinet would be very cool:cool: Anybody know a model Fender Speaker cabinet that used 2 D120F's?

[edgewound]

Hey Rudy,

2130's are functionally identical to K120's....2130's should have an "m-roll" cloth surround. Recone kit currently is C8RE120/C16RE120.

A great cabinet for those drivers would be either the small Bandmaster cab of the '60's or the larger Bandmaster Reverb cab of the '70's. I had the larger one with Oxfords in it (OEM) when I was 14-15 years old. Wish I still had that amp but it was awfully huge for a 2x12. I have the smaller '60's cabinet. Obviously the larger cab will give you more thump.

That rig will scream :yes: .:rockon1::spchless::eek:

[Hamilton]

Anybody know a model Fender Speaker cabinet that used 2 D120F's?
Fender did make a 2x12 Dual Showman cab, but they are extremely rare. I know they made them because I did a gig with my buddy's in '66, but that's the only one I've ever seen.

I do have a picture of a '76 Bandmaster Reverb w/large cab and the dust covers have JBL appearance, but there's nothing in writing to substantiate that.

[toddalin]

Fender did make a 2x12 Dual Showman cab, but they are extremely rare. I know they made them because I did a gig with my buddy's in '66, but that's the only one I've ever seen.

I do have a picture of a '76 Bandmaster Reverb w/large cab and the dust covers have JBL appearance, but there's nothing in writing to substantiate that.

Are you sure that it wasn't a Single Showman with a twin 12" cabinet? I remember that the Single Showman's that I saw had one 15".

[Rudy Kleimann]

Fender did make a 2x12 Dual Showman cab, but they are extremely rare. I know they made them because I did a gig with my buddy's in '66, but that's the only one I've ever seen.

I do have a picture of a '76 Bandmaster Reverb w/large cab and the dust covers have JBL appearance, but there's nothing in writing to substantiate that.

Just back from some sleuthing on the Ampwares site. Saw a few good ideas:

A nice Black Face Bandmaster Reverb with a large, but not huge cabinet at http://www.ampwares.com/ffg/bandmaster_bf.html

This would probably be my best bet, size-wise and vintage to match my amp.

There is also a listing of a 1968-1980 Bandmaster Reverb Head and cabinet at http://www.ampwares.com/ffg/bandmaster_reverb_sf.html complete with pictures and equipment details. It lists 2-12" JBL D120 (no "F" suffix) as one option seen. Boy, that cabinet is humongous! :blink:

The Dual Showman data at ampwares only lists 2-15" JBL D130F, so that's out. See http://www.ampwares.com/ffg/showman_reverb_sf.html That's not saying they never made a 2-12" Dual Showman, only that ampwares doesn't have any data on one.

I need to dig out the old amp and those speakers this weekend and see what shakes out. Should be fun!

And, thanks to all who helped me so far!!!

[Rudy Kleimann]

Hey Rudy,

2130's are functionally identical to K120's....2130's should have an "m-roll" cloth surround. Recone kit currently is C8RE120/C16RE120.

A great cabinet for those drivers would be either the small Bandmaster cab of the '60's or the larger Bandmaster Reverb cab of the '70's. I had the larger one with Oxfords in it (OEM) when I was 14-15 years old. Wish I still had that amp but it was awfully huge for a 2x12. I have the smaller '60's cabinet. Obviously the larger cab will give you more thump.

That rig will scream :yes: .:rockon1::spchless::eek:

Edgewound, the Bandmaster reverb cabinet is a monster by the looks of it. Maybe too big...

I don't know about the K120 bit. The http://www.jblpro.com/pub/technote/jblpro_alpha.pdf alphanumeric model number list says a 2130 is, "...12" old pro version of D120" and 2135 as "...15" old pro version of D130" Both versions of 12's and 15's shared the same motor. This agrees with Harvey Gersts' recollections as well.

I'll post some pictures of my speakers and the Bassman Head after I get 'em out again, probably this weekend. Maybe they'll tell the story. I'm certain these have never been reconed.

[edgewound]

Edgewound, the Bandmaster reverb cabinet is a monster by the looks of it. Maybe too big...

I don't know about the K120 bit. The http://www.jblpro.com/pub/technote/jblpro_alpha.pdf alphanumeric model number list says a 2130 is, "...12" old pro version of D120" and 2135 as "...15" old pro version of D130" Both versions of 12's and 15's shared the same motor. This agrees with Harvey Gersts' recollections as well.

I'll post some pictures of my speakers and the Bassman Head after I get 'em out again, probably this weekend. Maybe they'll tell the story. I'm certain these have never been reconed.

The K-series followed right after the D-series around 1973 or '74. While your equivalent is correct, the K120(2130) and K130(2135) was just a couple of years later in evolution. Currently both get reconed with E-series kits. Incidently, a 2135 can be reconed with a 2235 recone kit since it is the same motor as a 2231.

[Hamilton]

Are you sure that it wasn't a Single Showman with a twin 12" cabinet? I remember that the Single Showman's that I saw had one 15".
Hey Todd, I don't remember the logo on the amp faceplate, whether is was written with "Dual" or not....I just don't remember. I only saw/played the amp twice, and this was 40 years ago. But I do distinctly remember the two D120Fs because I grilled the guy who owned it because I had never seen/heard of a 2x12 Showman, only 2x15s.

[Hamilton]

A nice Black Face Bandmaster Reverb with a large, but not huge cabinet at http://www.ampwares.com/ffg/bandmaster_bf.html
Bandmaster Reverbs were only available in silverface.


There is also a listing of a 1968-1980 Bandmaster Reverb Head and cabinet at http://www.ampwares.com/ffg/bandmaster_reverb_sf.html complete with pictures and equipment details. It lists 2-12" JBL D120 (no "F" suffix) as one option seen. Boy, that cabinet is humongous! :blink:
I believe there were two styles of "large" cabinets, the early one shown here with the speakers plumb to each other, then the mid '70s cab with the speakers in staggered position.

[Rudy Kleimann]

The K-series followed right after the D-series around 1973 or '74. While your equivalent is correct, the K120(2130) and K130(2135) was just a couple of years later in evolution. Currently both get reconed with E-series kits. Incidently, a 2135 can be reconed with a 2235 recone kit since it is the same motor as a 2231.

Only thing is, the K series is rated to handle twice the power the D series were: K=100W Sine, 200W Pgm, and D=50W sine, 100W Pgm. I also remember reading one of JBLPRO's technical papers where this was noted as well as the fact that the K's were designed with a voice length equal to their magnetic plate gap depth for maximum efficiency and also sounded different than the D Series as a result. I'll have to look for that on their site or in my files... OTOH, no two data sheets on the D series or on the 2130 show the same magnet weight. In fact, the (Dxxx) "F" Series catalog shows the net weight of the driver at less than the weight of the magnet.:hmm: We all know that JBL has been known to contradict themselves or make outright errors in their literature as well as their service information. You may very well be right, Edgewound.

At any rate, what it is (my 2130's) is what it is... I'll just have to see what guitar players think of them in a cabinet playing on them. Maybe I'll run into somebody with a cabinet loaded with D120's or D120F's and I'll hear it for myself.;)

[Rudy Kleimann]

[quote=Hamilton]Bandmaster Reverbs were only available in silverface.

You're right... my bad. I had my Blackface Bassman on the brain when I looked at it.:o: The picture clearly shows a silver tweed grille cloth. The cab and my amp are of the same vintage tho.:)

[edgewound]

Only thing is, the K series is rated to handle twice the power the D series were: K=100W Sine, 200W Pgm, and D=50W sine, 100W Pgm. I also remember reading one of JBLPRO's technical papers where this was noted as well as the fact that the K's were designed with a voice length equal to their magnetic plate gap depth for maximum efficiency and also sounded different than the D Series as a result. I'll have to look for that on their site or in my files... OTOH, no two data sheets on the D series or on the 2130 show the same magnet weight. In fact, the (Dxxx) "F" Series catalog shows the net weight of the driver at less than the weight of the magnet.:hmm:


The voice coil winding depth is the same for the D/K/E120 and 130...they share the same voice coils respectively. The technicals became more apparent as the Company became two divisions. The main reasons the D's sound different than the K's are this: The change to the cloth m-roll surround on the K series which is more compliant with less cone break-up and the higher temp voice coils going to an aluminum former rather than the kraft-paper former on the D-series. Same with their cousins, 2130/2135, in there respective eras. Adds up to a higher power handling, lower distortion driver with more bass extension. The motors are fuctionally identical... .057" gap, .280 top-plate, 1.2T gap flux.The difference between the D/K series and the 2130 is the profile of the magnet pot itself. The 2130 has the more squared-off back profile, while the D/K has the rounded profile. The flux densities are the same...the moving assemblies were identical.

As the years went by....and the switchover to ferrite magnets... JBL discovered there was too much overlap of models that did pretty much the same thing...extended range 2130, 2135 series speakers were pretty much the same as the MI D/K120, D/K130 series speakers, and by 1980 or so were discontinued.

[horseshead]

How can I get the rubber cement used back in the '60's to make the surrounds of JBL MI speakers surrounds a little less likely to dry out and crack?
Rick

[Harvey Gerst]

How can I get the rubber cement used back in the '60's to make the surrounds of JBL MI speakers surrounds a little less likely to dry out and crack?
RickI'd use something like a dab of rubber cement to seal any existing cracks in the surround, but that's not the same as the "goop" we used to treat the entire surround. Somebody here once posted the actual name of the stuff we used and where you can still buy it.

[hapy._.face]

Looking at the picture, the Chet Atkins Fender Acoustic Electric looks a little out of place.


Looks like an Ovation to me- which is perfectly in place with an 80's hair band act. :rotfl:

That rig is a riot! Makes me wanna cut the knees out of my denim jeans and splatter them with bleach...OK...maybe not. :p

[Harvey Gerst]

Looks like an Ovation to me- which is perfectly in place with an 80's hair band act. :rotfl:

That rig is a riot! Makes me wanna cut the knees out of my denim jeans and splatter them with bleach...OK...maybe not. :p
Yeah, it sure looks like an Ovation to me too. Probably for their sensitive power ballad. The first verse is acoustic, and then all the electrics kick in for the rest of the song.

[Rudy Kleimann]

The K-series followed right after the D-series around 1973 or '74. While your equivalent is correct, the K120(2130) and K130(2135) was just a couple of years later in evolution. Currently both get reconed with E-series kits. Incidently, a 2135 can be reconed with a 2235 recone kit since it is the same motor as a 2231.

So, Edge, if I understand correctly, the D-series had paper surround? If so, this definitely indicates an error in jblpro's alpha-numeric part number listing description. According to you, the 2130 is really another version of the K120. Maybe the 2130 went through an evolution in design during its' production lifetime? Do these pics confirm your beliefs that a 2130=K120?

[Harvey Gerst]

The D130F and D120F was an all paper, one-piece cone/surround. The pictures above ain't it.

[Rudy Kleimann]

The D130F and D120F was an all paper, one-piece cone/surround. The pictures above ain't it.

Thanks, Harvey. Mine are anything but a D-series, as I now know thanks to you guys. All this time I had been misled by that error on the JBLPRO site. It's an imperfect world: people make mistakes, screws fall out:D

I'm surpised you saw the pics. They're there now. My first attempt at adding pics to a post, and I flubbed it. A quick lesson from Don McRitchie's thread on attachments showed me the error of my ways:p

Maybe now I'll finally get that avatar up;)

[Harvey Gerst]

I'm surpised you saw the pics. They're there now. My first attempt at adding pics to a post, and I flubbed it. A quick lesson from Don McRitchie's thread on attachments showed me the error of my ways:p
By the time I finished my one line reply, your pictures were fixed, so I amended my answer.

[Rudy Kleimann]

Thanks, Harvey. You the man!

So, what do you make of the markings on the back of the cones? Does the "K" handwritten in yellow and/or the "21032" suggest a K-series assembly?

[Rudy Kleimann]

Here's a picture of the rear of a 2130 and a K140 showing the different shape of the magnet pot per edgewounds' previous post.

Note that the magnet assambly on the 2130 is 1/4" taller than the K 140: 2-1/2" vs. 2-1/4" (Accurate measurement from backside of frame)
Also note the magnet top plate of the 2130 is thicker than on the K 140: 3/16" vs. 5/32" (approximate measurement of silver plate from backside of frame to painted magnetic return circuit "pot". If need be, I'll find my micrometer and measure it more precisely)

[Harvey Gerst]

Thanks, Harvey. You the man!

So, what do you make of the markings on the back of the cones? Does the "K" handwritten in yellow and/or the "21032" suggest a K-series assembly?
I left JBL before they did the "E" and "K" series. The original "F" series just used the stock D130 and D131 cone assemblies, except with the "gooped" surround.

Tony Lowe took over my job, so he'd be the one to ask.

[Rudy Kleimann]

I left JBL before they did the "E" and "K" series. The original "F" series just used the stock D130 and D131 cone assemblies, except with the "gooped" surround.

Tony Lowe took over my job, so he'd be the one to ask.

I'm hoping that edgewound will weigh in on this, since he has apparently studied this and seen a few of these models torn down for recone.

The top plate measurements I made are strictly what I can see from the side of the magnet structure as it sits on the frame, using a ruler and a "calibrated eyeball";) However, it appears that the magnet sits down into a machined recess in the backside of the frame, so the difference I am measuring could be due to a different depth recess cut into the 12" 2130 vs. the 15" K 140. The pot structure is definitely taller on the 2130 though FWIW.

[Mike Caldwell]

Going back to the "wall O amps"
I was working on the stage at a festival a few years ago and Styx was one of the acts. They had two wall's of Mesa Boogie 4x12 cabinets and amps on stage. All of the cabinets except one was a empty dummy cabinet that did not even have the front baffle openings cut out to mount speakers. The other side's wall were all empty cabinets and setting behind was a small Mesa rig that was really being used.
I remember reading an article about a Def Leppard tour that used no active speaker cabinets everything was going direct from the amps to cabinet simulator DI boxes.



Mike Caldwell

[edgewound]

Sorry for the short answer Rudy, short on time.... but....the top plate is recessed into the frame a little....should be a .280" top plate....you can't measure it accurately without disassembly.

Yours is definitely a K-Series equivalent.

[Hamilton]

I remember reading an article about a Def Leppard tour that used no active speaker cabinets everything was going direct from the amps to cabinet simulator DI boxes.
Same with Motley Crew and Judas Priest, you'll see those empty cabs on eBay from time to time.

[Tom Loizeaux]

I remember seeimg Hendrix in '68, and even back then, I noticed that the end Marshall cabinet has no speakers in the cut-outs. Then, at the end of his concert, he went over to that empty cabinet and jammed the head of his Strat into one of the empty holes, tearing the grille cloth.
Hey, it was still cool!

Tom

[horseshead]

I'd use something like a dab of rubber cement to seal any existing cracks in the surround, but that's not the same as the "goop" we used to treat the entire surround. Somebody here once posted the actual name of the stuff we used and where you can still buy it.

Anybody know where I can get this stuff? It is a high viscosity liquid that dries after it is applied. It protects the surround against cracking.

[Don C]

There's some information here:
http://www.audioheritage.org/vbulletin/showthread.php?t=7991

[watchman]

Wow, what an incredible thread.

I am also restoring a Quad Reverb, a decided to have the (4) original oxford speakers reconed. I did see a Quad with D120Fs in it, but the thing was so heavy it took a hand truck to move it. Four E120s would add another 24 lbs to the mix.

My Quad Reverb has but one pair of secondary windings on the original output transformer. If you go with D120s, or D131s, be sure to get 16 ohm edgewound aluminum voicecoils so that four in parallel yield 4 ohms. 8 ohm voicecoils will yield 2 ohms that will stress your output tranny.

Also, check the baffleboard on your Quad. It is just 0.5" pressboard and mine was cracked in about six places. The load from four heavy speakers will certainly be higher.

I have D131s in my Twin Reverb and love them. Tried D123s and did not like the sound from a low-excursion driver.

As for the Blonde Showman - they originally came with a single D120 mounted in a tone ring. This is the rarest cabinet. Later, a single D130 was mounted in a tone ring, followed by the Dual Showman having a pair of D130s without tone rings.

For my kid, I am building a Blonde Showman combo using a 1968 chassis rewired to 6G14 spec feeding a D130F reconed to 4 ohms.

... watchman

[horseshead]

There's some information here:
http://www.audioheritage.org/vbulletin/showthread.php?t=7991

Thanks Don! This site can be a little intimidating with all the articles/threads to search. For example, if I didn't type the right phrase or word in the search field then I might not have gotten the above thread. Thank you!

However, I still didn't see mentioned what I had hoped, what I need, which is the stuff that JBL used to dope their D131's (as one of the two things that were done to make them into D120's/120F's). What was mentioned was only the GE weather strip sealer or the PVA used by Electrovoice for cloth or foam surrounds as recommended to dope the 2205's. The speakers I would be doping are the JBL D131's and I believe the surrounds are paper, no? Also, the there was a PVA recommended for a "band-aid fix" mentioned which was elmer's glue diluted (mixed) with warm water.
Rick

[GordonW]

A more correct doping material is #AA-75, from Waldom. It's "gooey", and stays somewhat sticky, pretty much forever. It won't overly stiffen the surrounds (in fact, it doesn't have much of a bending modulus whatsoever, so it really won't change the parameters at all, in any significant sense), and it's more permanent (ie, won't run/creep) than the Altec "goop".

Many reconing shops carry Waldom AA-75... it should be possible to get someone to treat the paper edges, in most metro areas.

Regards,
Gordon.

[horseshead]

Wow, what an incredible thread.

I am also restoring a Quad Reverb, a decided to have the (4) original oxford speakers reconed. I did see a Quad with D120Fs in it, but the thing was so heavy it took a hand truck to move it. Four E120s would add another 24 lbs to the mix.

My Quad Reverb has but one pair of secondary windings on the original output transformer. If you go with D120s, or D131s, be sure to get 16 ohm edgewound aluminum voicecoils so that four in parallel yield 4 ohms. 8 ohm voicecoils will yield 2 ohms that will stress your output tranny.

Also, check the baffleboard on your Quad. It is just 0.5" pressboard and mine was cracked in about six places. The load from four heavy speakers will certainly be higher.

I have D131s in my Twin Reverb and love them. Tried D123s and did not like the sound from a low-excursion driver.

As for the Blonde Showman - they originally came with a single D120 mounted in a tone ring. This is the rarest cabinet. Later, a single D130 was mounted in a tone ring, followed by the Dual Showman having a pair of D130s without tone rings.

For my kid, I am building a Blonde Showman combo using a 1968 chassis rewired to 6G14 spec feeding a D130F reconed to 4 ohms.

... watchman

Usually something with the word reproduction in it will attract more attention than a thread that includes JBL's but not limited to JBL's being the final goal.

Where did you see a Quad with 4 JBL D120's? I was looking for that.

I've been advised by the guy I use as an amp technician here locally that the final speaker load in a fender quad reverb should equal 4 ohms. That's all the output transformer of the quad needs to do is match that. So in order to do that you should use 4x16 ohm speakers. And, he went on to say that the tube amps have less tolerance for output transformer/speaker load mismatching than solid state amplifiers. So I'll have to ask him why and get back to the group on it if it's worth getting back to the group on that, because that's opposite to what's been stated by at least a couple of group members so far - that tube amps are MORE tolerant of impedence mismatching than are transistor amps. He said tube amps are more forgiving for impedence mismatching where speaker impedences are too low for the output transformer than speaker impedences that are too high for the output transformer, and that the latter are more likely to overwork the tubes.

I'm not sure if I've already stated this in this thread, but I'm trying to go stereo with my dual showman reverb and the quad, but I'm not sure if I should be using a feder pro instead of the fender quad. Can anybody make a positive identification of the small amp on top of the extension speaker cabinet in the background on stage in the Yessongs video? And is the cabinet a 2x12" or a 2x15"?
Rick

[watchman]

Hey Rick,

I saw a 4xE120 Quad Reverb at a friends house. He took the four JBLs from a Fender transistor amp (Libra?) and bolted them into his QR. Talk about loud!

The impedance of the speaker should match the output transformer. For a QR, you get 4 ohms from 4x16 ohm speakers in parallel. For tube amps, you can always put a higher impedance speaker, with a corresponding reduction in power.

Tube amps have a problem in the other direction. 4x8 ohm speakers would have yield a 2 ohm load that would draw 1.4x the current (Power = I^2*R) to produce the same power (100W). This stresses the output transformer, which is old to begin with.

As for your stereo amps, the QR, Twin Reverb and Dual Showman Reverb all use identical circuits with 4x6L6GC tubes and 4 ohm output transformers. The Dual Showman Reverb cabinets were all 2x15" and 2x8 ohms for 4 ohm impedance.

The early blond showman amps were 8 ohms, and the double showman used a pair of 16 ohm 15" D130F speakers to get 8 ohms. The single cabinets had either an 8 ohm D120F or an 8 ohm D130F. Clever, huh?

The Fender Pro Reverb and Super Reverb would work in a stereo setup because they use identical 2x6L6GC circuits, but produce only half the power of the QR.

The QR is louder than the TR or Showman, and the Super Reverb is louder than the Pro. Do some math on the cone area of the 4 speakers vs. two and you will realize they move a lot more air.

... watchman
BTW - I am en engineer, not an amp tech.

[horseshead]

A more correct doping material is #AA-75, from Waldom. It's "gooey", and stays somewhat sticky, pretty much forever. It won't overly stiffen the surrounds (in fact, it doesn't have much of a bending modulus whatsoever, so it really won't change the parameters at all, in any significant sense), and it's more permanent (ie, won't run/creep) than the Altec "goop".

Many reconing shops carry Waldom AA-75... it should be possible to get someone to treat the paper edges, in most metro areas.

Regards,
Gordon.

And yet there was suppossed to be someone here on the forum who had once posted where one would be able to get a hold of the original goop that JBL used to dope their D120's/130's.
Rick

[moldyoldy]

If you're referring to Airflex 510, it's no longer available, unless you can find some old stock on a shelf somewhere. It was made by Air Products. The Waldom dope referred to above is the closest substitute I'm aware of.

[SMKSoundPro]

Dear Sirs,

This thread is getting silly.

Get out there and find 4 k-120 baskets and have them reconed with a current C16RE120 kit and let that Fender RIP your head off!!!

If not that...find 2202 baskets, which are always cheaper on ebay, and have them reconed as E-120s.

There is always another way to skin a cat.

As far the man on ebay with the reproduction foilcals, who cares. The white pencil marking on the cone from the person who glued it in is what is really important.

Willing to go out on a limb...for a second.

Scott.

[Zilch]

As far the man on ebay with the reproduction foilcals, who cares. The white pencil marking on the cone from the person who glued it in is what is really important.
Fine. I'll sell white pencils to guitar heads.

Maybe a little "Upgrade Kit."

Soon "F" will simply mean "Fraudulent."

I THINK we're here to PRESERVE the legacy....

[watchman]

That way my understanding, otherwise we would be faux-Lansing Heritage ;)

Our esteemed colleague from SMKSoundPro ovbiously has not read very deep into the thread, where we discussed concerns with weight. Here is a hint: 4 E110 or K110 baskets sitting on a 1/2" of pressboard dado-d 1/8" and glued into the pint cabinet sounds great until it gets dropped.

Well, now we know where those silly pencil marks are coming from :)

... watchman

[horseshead]

If you're referring to Airflex 510, it's no longer available, unless you can find some old stock on a shelf somewhere. It was made by Air Products. The Waldom dope referred to above is the closest substitute I'm aware of.

Again, as always with me, these should be fairly simple, straightforward questions - If I were to buy D131's and then dope their surrounds with Waldom AA-75, and also wire it up with a D131F which I presume is a D131 with a surround that has been doped with Airflex 510, would there sonically be a noticeable difference between the two speakers - the one speaker doped with one brand and the other speaker doped with the other brand?

Is it correct to say that the D131F is identical to the D131 except that it has been doped and with Airflex 510?

The gentleman from Standel has told me that doping the surround of a D131/120/130 changes the sound quite a bit as well as increasing the power handling because doping the surround stiffens the paper cone thereby changing the speaker's frequency characteristics. Because of this information as I have been told, I was thinking of doping the surrounds of my JBL single ring recone D120 (1957/58) reproductions. I had better check first with the reconer on this before even considering this.

Rick

[moldyoldy]

Rick,
I understand your frustration, but I can't give the answer you seek, because I don't know it. I posted the reference to Airflex 510 because I knew it to be a preferred doping compound for a long time, though I doubt that it was available in '57-58, or that it was the compound originally used at that time. I also doubt that whatever dope was originally used (if known) is still available today. It's kind of like trying to match paint used back then, in that there's none of the original product around anymore, so the best we can do is get a close match.

Doping a surround does not increase power handling, as that is a function of the heat tolerance and breakdown temperature of the voice coil. Nor does doping a surround stiffen the cone, as it only alters the area it's applied to (the surround). It could however, alter the tone of a speaker by damping edge or rim resonances, in which case it would produce less distortion, or a 'cleaner' sound. Doping is also a permanent modification, once applied, there's no going back.

The characteristics we often find desireable in many classic instrument speakers ARE their distortion products, whether from cone breakup, rim resonances, or otherwise. Personally, I think it's highly unlikely that anyone can EXACTLY duplicate the sound of any 50 year old speaker when it was new. If you're a musician, find a tone you're happy with and go with it. If you're a collector.....well....they don't care what it sounds like anyway, as long as it's 'original'.

[SMKSoundPro]

I am greatly sorry if I offended anyone by my earlier post.

Certainly, I am OUTRAGED that someone would sell aftermarket foilcals! I saw a pair listed on ebay that I would guess, the seller is part of this esteemed forum group.

My point was/is: That in the recone shop, we tore off foilcals, then reconed the basket into something else, then used our white pencil on the back of the cone to denote the cone kit installed. We were never naive enough to believe a guitar player knew more about the subtle differences of 12" JBL speakers.

This may seem like a harsh statement, but please believe that I found it to be the case on more than one occasion!

We had guys walk in not knowing a celestion greenback from a k120! Its as if they were just following some suggestion they found somewhere else. A friend, magazine article, or a new found buzzword.

Please accept my apology, and don't ever take away my white pencil!

Scott.

[Harvey Gerst]

Again, as always with me, these should be fairly simple, straightforward questions - If I were to buy D131's and then dope their surrounds with Waldom AA-75, and also wire it up with a D131F which I presume is a D131 with a surround that has been doped with Airflex 510, would there sonically be a noticeable difference between the two speakers - the one speaker doped with one brand and the other speaker doped with the other brand?
I think "doping" is probably a misleading term. The "goop" we used was a super high viscosity oil. It worked well to damp out any ringing from the edge of the cone. It was basically used on the D123 to seal the cloth surround without stiffening the surround.


Is it correct to say that the D131F is identical to the D131 except that it has been doped and with Airflex 510?
No, that's not correct. The "F" series had the top plate opened slightly, to prevent rubbing and shorting in the coil from frame warpage.


The gentleman from Standel has told me that doping the surround of a D131/120/130 changes the sound quite a bit as well as increasing the power handling because doping the surround stiffens the paper cone thereby changing the speaker's frequency characteristics. Because of this information as I have been told, I was thinking of doping the surrounds of my JBL single ring recone D120 (1957/58) reproductions. I had better check first with the reconer on this before even considering this.

Rick
The gentleman from Standel is incorrect. Coating the surround (correctly) neither increases the power handling nor does it stiffen the surround. The D120F is almost absolutely identical to the D131; the D130F is almost absolutely identical to the D130.

[Rudy Kleimann]

edgewound, AFAIK this absolutely confirms your statement that my 2130 is equivalent to the K120:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=ADME:B:WNA:US:43&item=7413313412&id=

ebay seller says he removed this original K120 from his Fender cabinet.

The K120 surround is identical to my 2130 surround.

The K120 cone number is the same as my 2130, with the additional "16" penciled on it in white, indicating a 16ohm voice coil. My 2130 cone has "K" penciled on it in yellow.

[horseshead]

I think "doping" is probably a misleading term. The "goop" we used was a super high viscosity oil. It worked well to damp out any ringing from the edge of the cone. It was basically used on the D123 to seal the cloth surround without stiffening the surround.

And the Waldom #AA-75 doping compound is only closer to what was actually used at the time by you and JBL in the factory? In your opinion, would there be a noticeable difference in the sound of the speaker if I coated the surround with the Waldom versus what was originally used at the time on this model speaker in the JBL factory?


No, that's not correct. The "F" series had the top plate opened slightly, to prevent rubbing and shorting in the coil from frame warpage.

Then, wouldn't that mean that the D131F is identical to the D120 which is also identical to the D120F? Only the names are different?


The gentleman from Standel is incorrect. Coating the surround (correctly) neither increases the power handling nor does it stiffen the surround. The D120F is almost absolutely identical to the D131; the D130F is almost absolutely identical to the D130.

I don't want to misquote anyone and I'm suppossed to call him back to finnish our conversation. I'll get back on what he says about JBL guitar speakers later on.

Rick

[horseshead]

Rick,
I understand your frustration, but I can't give the answer you seek, because I don't know it. I posted the reference to Airflex 510 because I knew it to be a preferred doping compound for a long time, though I doubt that it was available in '57-58, or that it was the compound originally used at that time. I also doubt that whatever dope was originally used (if known) is still available today. It's kind of like trying to match paint used back then, in that there's none of the original product around anymore, so the best we can do is get a close match.

Doping a surround does not increase power handling, as that is a function of the heat tolerance and breakdown temperature of the voice coil. Nor does doping a surround stiffen the cone, as it only alters the area it's applied to (the surround). It could however, alter the tone of a speaker by damping edge or rim resonances, in which case it would produce less distortion, or a 'cleaner' sound. Doping is also a permanent modification, once applied, there's no going back.

The characteristics we often find desireable in many classic instrument speakers ARE their distortion products, whether from cone breakup, rim resonances, or otherwise. Personally, I think it's highly unlikely that anyone can EXACTLY duplicate the sound of any 50 year old speaker when it was new. If you're a musician, find a tone you're happy with and go with it. If you're a collector.....well....they don't care what it sounds like anyway, as long as it's 'original'.

I have a couple of questions about edge resonances as I've never heard of them before.

A little background before I ask the questions:

I only buy guitar equipment to play through it, I'm not a collector. But, I have been playing mostly classical guitar lately and IF I play electric, it's been in my house. It's great that I have a goal to first buy the equipment that is as close as possible to that which was used with the Gibson ES345 guitar on the Yessongs album as a reference point to understand what I would need to play through in order to obtain this, my favorite electric guitar sound (since the '70's). That is a fender dual showman reverb with the 2x15" D130F cabinet for the bass pickup and a fender quad reverb for the treble pickup on the stereo guitar.

Getting back to edge resonances, I had heard that the sound of a fender dual showman reverb amp with it's two JBL D130F cabinet with the volume cranked up to 7 or higher actually takes on a freaky, synth-like sound. Is this true, and if it is, does it have anything to do with edge resosnances? And if this freaky sound does happen with this amp/speakers at high volume, given the modest, low power requirements of my playing environment, would it still be possible to obtain that sound with a lower power fender amp driving the same two JBL D130F's or even just one D130F?

BTW, I don't think the quad reverb was used for the Yessongs tour. It was a fender pro, but I saw Yes many times during the '70's - the first time with the dual showman and the pro, and subsequently with the dual showman and the quad and even possibly two dual showmans, and the sound was about the same quality, all great. So I'm thinking that the sound quality is not dependent on which fender amp is used - the sound quality is in the JBL's. Rather, which fender amp used has to do with the size of the power of the amp, how loud you want to turn it up, your volume requirements, and whether you need to have it turned up high for a little distortion or you won't be doing that and you want it totally clean. Myself, I would like to have that ability to turn it up to break up when I feel like switching to that sound and then maybe to clean. But, I think I'm more into the turned up sound.


Rick

[Hamilton]

I saw Yes in the mid 70's and unfortunately we were sitting straight off stage left, I could barely see the backline. I was mostly curious to what Chris Squire was playing but I could indeed see Howe's Dual Showman Reverb.

Other than that I can't tell ya much, except the mix that night was overly bright and thin.

[edgewound]

edgewound, AFAIK this absolutely confirms your statement that my 2130 is equivalent to the K120:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=ADME:B:WNA:US:43&item=7413313412&id=

ebay seller says he removed this original K120 from his Fender cabinet.

The K120 surround is identical to my 2130 surround.

The K120 cone number is the same as my 2130, with the additional "16" penciled on it in white, indicating a 16ohm voice coil. My 2130 cone has "K" penciled on it in yellow.

Thanks, Rudy.

I'm glad you found proof to substantiate my factory...and experience... supplied info.:)
It's good to be a detective and confirm the facts for yourself.;)

[edgewound]

This thread is getting to the point where the ridiculousness of legendary speakers' inflated legends gets bigger than the speaker themselves.

The amount of disinformation is legendary....mythical.

The D120F is a D131 with a coated paper surround and the gap top plate machined out .002" to yield a larger gap from .053" to .057"....as Harvey stated numerous times before to remedy the warping from installers that like to tighten screws too tight...and short out voice coils as a result. Most likely the D131 will have to be machined out to .057" once it needs to be reconed....with a JBL kit, which BTW, is an E120 recone kit

The same story with the D130 and D130F.

The K-series 120 and 130 are indentical structures to their D-series counterparts. The surrounds are m-roll cloth for less cone distortion and lower bass response...and the voice coils are wound on aluminum formers for higher power handling.

The tone one gets out of an amp/speaker/guitar system is mostly dependent on the players ability. Two guitar players will get two different tones based on what comes through your hands and fingers first.

Forty, fifty year old speakers are living on borrowed time. A D120F reconed with an E120 recone kit is a much better and versatile speaker in most cases.

Let's forget about the mythical status of these things and just recognize them for what they are....great speakers....great tools to make music with. Every Artisan uses tools in a different way to make his/her own art with an individual flavor and statement.

[Harvey Gerst]

I have a couple of questions about edge resonances as I've never heard of them before. Damn, you sure ask a lot of questions!!! :confused:

There's no simple answer, so lemme try and make it as non technical as I can:

Guitars, violins, stringed instruments, in fact, all instruments (including loudspeakers) radiate notes differently at different frequencies!! Read that again: Guitars, violins, stringed instruments, in fact, all instruments (including loudspeakers) radiate notes differently at different frequencies!!

What does that mean exactly? It means that different parts of the instrument's body are used to produce different notes! Here is a link that show how the guitar top changes with each note:

Chladni guitar top radiation patterns:http://www.phys.unsw.edu.au/music/guitar/patterns_engl.html

As you can see, different notes come from different places on a guitar, which brings us to the same condition in loudspeakers. A "perfect" cone loudspeaker should be absolutely rigid, have no mass, and move like a piston at all frequencies.

But perfection is seldom reached in the real world. Speaker cones aren't absolutely rigid, or without any mass, and they don't move like pistons all that well. They can flex, depending on what frequency is involved. Just as when people get angry about something, when a loudspeaker gets hit with a note it doesn't like, it sets it off, and the speaker can howl, producing a note all its own.

They're called resonances, wolf tones, breakup, and a lot of other things, but the result is the same: distortion of the original signal. Sometimes, it can be pleasant; not all distortions are always bad-sounding.

Remember I said earlier that a perfect speaker would "move like a piston"? The part of the speaker that drives the cone is the voice coil. So the thing that makes the whole cone move is that little 4" circle of wire underneath the shiny dome in the center of the speaker. It moves in and out, and the cone moves with it.

But, since the cone can flex (it's not absolutely rigid), sometimes the cone will move like a guitar string, or a wave, with the note spreading out from the center of the speaker, hitting the rim, and reflecting back. That's an edge resonance. Putting goop on the surround is like adding fly paper to the edge of the speaker, or the "Hotel California" treatment (the wave can check in, but it can't check out).

The goop on the surround can solve or reduce some of the problems with edge resonances and reflections, but it can't eliminate the cone flexing problem - nothing can. When you start making the cone more rigid, you increase the mass. Ain't no free lunch.

Designing speakers is all about trade-offs and compromises: pick up a little bit here, lose a little bit there. Want a lot of efficency? It's gonna cost you low end. Want low end? It's gonna cost you efficency.

Does this kinda make things a little clearer, Rick?

[Rudy Kleimann]

Thanks, Rudy.

I'm glad you found proof to substantiate my factory...and experience... supplied info.:)
It's good to be a detective and confirm the facts for yourself.;)

I knew you knew what you were talking about, just as I knew Harvey knew what he was talking about. Factory training and experience can't be denied, hehe.:thmbsup:

My only mistake was being misled by the errors on the JBLPRO Alphanumeric part number listing prior to reading this thread. You and Harvey set things straight in short order.:applaud:

I just put these pics up as proof to others. I found 'em by accident on ebay, and couldn't resist.

It seems some of these posters keep going around in circles, and I knew the pictures were proof positive for them -or at least they should be. I was already convinced. If these other guys could "get it"... damn, I'm starting to sound like Giskard...:p

[Rudy Kleimann]

Excellent post Harvey. How many more questions will this post create?

Maybe you can start an on-line course in loudspeaker driver design theory and application for extra income? That'd make it worth your while, at least:D

[Harvey Gerst]

Excellent post Harvey. How many more questions will this post create?

Maybe you can start an on-line course in loudspeaker driver design theory and application for extra income? That'd make it worth your while, at least:D Naw, this is my way of paying back people like Ed May, Bart Locanthi, Bill Burton, and George Augspurger, who taught me a lotta stuff for free.

I did something similar to this at home recording, explaining how mics work. Some of it is an interesting read. You can find it at: http://www.homerecording.com/bbs/showthread.php?t=27030

I'm really getting too damn old for some of this stuff.

[Rudy Kleimann]

Naw, this is my way of paying back people like Ed May, Bart Locathi, Bill Burton, and George Augspurger, who taught me a lotta stuff for free.

I did something similar to this at home recording, explaining how mics work. Some of it is an interesting read. You can find it at: http://www.homerecording.com/bbs/showthread.php?t=27030

I'm really getting too damn old for some of this stuff.

I was just being facetious... :D

The world needs more kind folks like you in it. Lord knows I've learned from you in the short time since I first ran across you here, and I, for one, really appreciate you sharing your knowledge.:applaud:

The home recording forum looks mighty interesting too. Thanks for posting that link!

[Hamilton]

I'm really getting too damn old for some of this stuff.
I can't believe how much I used to worship my D140Fs when I was a kid, and now here's the guy that built them!! But now I'm gettin' too old to be excited. :blink: :D

[BillScintilla]

The D123 will handle a lot more than 15 watts. It should handle as much as a D110F. It should work fine with a 50 or 60 watt amp, as long as you don't push it really hard.

This is my first post and I would like to say a very sincere 'thank you' to Harvey for making my life a better place to live. I have used D120's for close to 40 years and they are a wonderful piece of art and science. I still use one today and would use more of them if I could find them. Also, many thanks to Harvey to being so thoughtful and generous to put his knowledge out there to those of us who truly value it. In other cultures you would likely be thought of and treated with great respect as an 'Elder'.

So, my questions to Harvey please (I hope you still read this thread!) ... why is the the D123 your favorite guitar speaker of all, especially compared to the D140? Is it true there is less bass and, if so, if I use four D123 in a cabinet to move more air will I get the 'missing bass' back compared to a couple of D120's?

And, if you don't mind, what are your musical tastes especially as they relate to guitar playing? I'm just trying to get some insight into what you like to hear.

I have a'63 blonde bassman head (50 watts that I no longer turn up to 10) that I use for rock 'n' roll, country, blues and jazz. Will I be safe in the 5-7 range with two D123's do you think, please?

[Rudy Kleimann]

Welcome to the site! Good to see a man like Harvey get the respect due him. But that's nothing unusual around here- lots of true experts, seniors, and current as well as former JBL employees come here and post from time to time. Even Greg Timbers himself has posted a few.

Do a search for Harvey Gerst on the 'net and you'll find he runs a recording studio in North-Central Texas. Well worth a visit...

Enjoy!

Rudy

[Harvey Gerst]

So, my questions to Harvey please (I hope you still read this thread!) ... why is the the D123 your favorite guitar speaker of all, especially compared to the D140? Is it true there is less bass and, if so, if I use four D123 in a cabinet to move more air will I get the 'missing bass' back compared to a couple of D120's?

And, if you don't mind, what are your musical tastes especially as they relate to guitar playing? I'm just trying to get some insight into what you like to hear.

I have a'63 blonde bassman head (50 watts that I no longer turn up to 10) that I use for rock 'n' roll, country, blues and jazz. Will I be safe in the 5-7 range with two D123's do you think, please?The D140 was designed for bass, not guitar. But, why do I like the D123 for guitar?

It's one of the smoothest speakers JBL ever made, no ear fatigue. It has a surprising amount of bass because of its cone excursion. A pair of D123's should work well with a 50 watt amp.

As far as my tastes in guitar playing, my first teacher was Barney Kessel, but my influences range from Albert King and Brownie McGee to Merle Travis to Jimi Hendrix. I've played blues, country, folk, jazz, and rock for most of my life.

[BillScintilla]

Hi Harvey,

There was a typo in my post, I meant to type D120, not D140. But, you have answered my questions and addressed my concerns perfectly.

I very much appreciate your detailed information and timely response.

I will now buy buying some D123's for my rig plus a few more as spares since I understand getting used ones with good cones is cheaper than getting one re-coned. If you can even find OEM cone kits!

I was getting depressed because I couldn't find any D120's at anywhere near a reasonable price and you have solved my problem.

You and I have very similar musical tastes so I am confident getting them will be a very positive and revelatory experience.

Thanks again!

[duckytruck]

Hey Todd, I don't remember the logo on the amp faceplate, whether is was written with "Dual" or not....I just don't remember. I only saw/played the amp twice, and this was 40 years ago. But I do distinctly remember the two D120Fs because I grilled the guy who owned it because I had never seen/heard of a 2x12 Showman, only 2x15s.
If it was a blond showman...probably a bandmaster base..in a dual 12

[jcrobso]

There is a seller on eBay that is reconing D123 or similar frames for guitar.
After reading Harvey's comments about the D123 I got one. This is a nice sound guitar speaker. Better bass than the stiff coned D/K/E speakers, but not as much power. I'm having this person recone a E120 into a bass speaker, I will report back when it's finished. :) John

[dtdionne]

What a fantastic thread...thank you for all your hard work over the years at JBL, its amazing to see those people posting here!!

Anyway, I know this thread is a bit old but the search continues for many...personally im trying to get EVH1 tone and im certain that I need a pair of D120's to go along with my pair of scumback M75s (amazing pre-rola green replicas). Has anyone checked out the weber 12A125, 12F125
12A150, 12F150 speakers? https://taweber.powweb.com/weber/ I'm thinking about trying a pair of them...

[jcrobso]

http://www.usspeaker.com/beyma%20liberty-1.htm

I have not listened this speaker, but I have do have some other Beyma speakers and they sound very similar to JBLs.

However used JBLs D/K/E 120 can be found for less than this speaker's new price. John