846B Restoration

[Marvin]

I have a pair of Altec 846B's I purchased new in 1976. One of the horns has been repaired. Other than that, they have never been altered. I have always loved the sound, but lately they just don't seem to sound the same. Is there an upgrade program, refurbish, or am I stuck with what I have. Other than the foam part of the grills falling apart, they are perfect. I don't want to sell or trade them, I just want the sound improved to much as it was.
Thanks

[Marvin]

With so many audio pros on this forum, why can't I get a response to my posting?

How about a recommendation as to a company that will refurbishes my Altec 846B's. They are 35 years old and need to be restored to their original sound quality. Any suggestions?
Thanks,
Marvin

[hjames]

With so many audio pros on this forum, why can't I get a response to my posting?

How about a recommendation as to a company that will refurbishes my Altec 846B's. They are 35 years old and need to be restored to their original sound quality. Any suggestions?
Thanks,
Marvin

I am not an Altec owner, but I have heard them mention Great Plains Audio as the folks who picked up the legacy Altec technology. I gather the owner doesn't do emails, but if you search this site for Great Plains you should be able to find a phone number so you can discuss it with them.

[BMWCCA]

:idea: (http://www.greatplainsaudio.com/contact.html)



http://www.greatplainsaudio.com/contact.html

[Earl K]

Marvin,


They are 35 years old and need to be restored to their original sound quality. Any suggestions?


- The problem for all Altec owners is that no one can actually achieve a proper ( bona fide ) restoration in the strictest sense of the word .
- The original parts no longer exist .
- The best you can hope for is a facsimile &/or perhaps even an upgrade ( whatever that may mean ).

- One problem here is that the Altec Corp you gave your money to, is gone / & there are just pretenders to the throne .
- As mentioned already, the best ( & only ) maker of ( essentially real ) Altec parts is Bill H. at GPA ( who bought a goodly portion of Altecs' original parts tooling, when Altec closed its' doors ).

- The 8 ohm diaphragm ( # 21597 ) for your 806-8A driver hasn't been made for about thirty years . It's been replaced by GPAs' # 34647 diaphragm ( which, by my reckoning is a slightly heavier & more high powered version ).
- You can see for yourself what the proper part numbers were ( back in 1975 ) for your speaker by clicking on the picture I've included .
http://www.lansingheritage.org/images/altec/reference/1975-drivers/thumbs/page06_small.jpg (http://www.lansingheritage.org/images/altec/reference/1975-drivers/page06.jpg)

- I've heard that a pair of GPA replacement diaphragms will cost @ $ 200.00 uninstalled ( installed would be more since it means 2-way shipping of your drivers to Oklahoma ) .
- A better option ( IMO ) is to buy a pair of these drivers from GPA ; http://www.greatplainsaudio.com/902_8A.jpg (http://www.greatplainsaudio.com/downloads/902series.pdf)
- ( I think they will physically fit depth-wise / but you need to check this out for yourself since a pair is around $ 400.00 I believe ).



- You could consider this driver an upgrade since it has more extended HF response than the original 806 ( which takes a dive in response after 10K ). It would be worth your while to remove one horn driver to identify if it is in fact an 806 / perhaps your 846b is newer / with a different driver .


- Compounding any real "restoration process" is the fact that capacitors like the type found in your crossover can eventually change their values and also change their sonics ( as they age ) .
- The original caps ( of which I have opened up a couple ) had a dielectric material that was made from a lightly waxed, craft paper ( layered between aluminum foil ) .
-This type of cap ( dry paper ) has a unique sound to it / & / it's an open ended question as to whether or not they should be replaced / & if so, replaced by what type of cap ?
- Replacing this type of cap ( with a modern successor ) is virtually impossible / since "dry paper" caps haven't been made & sold in decades ( they have been functionally replaced by plastic film type caps using 'Mylar" or "Polypropylene as the dielectric .
- There are "wet paper caps" ( called PIO ) that many audiophiles love / along with ( of course ) audiophile prices . Google, "PIO caps" or "PIO Capacitor" to begin your education on the matter .
- These market changes leave the "restorer" with a significant dilemma / because once one decides to replace the caps then one has to find a cap type whose sonics suit the system . There are just as many opnions on what is a suitable replacement as there are grains of sand on the beach .
- You'll need to lurk about and read as much as you can on this forum & others as to what some of those opinions are ( learning to use the search functions of various forums is therefore a must if you want to plumb the archived opinions of those who have gone before you . )
- FWIW, IMO, "wet MPP" motor-run caps are about the closest approximation to the older dry paper types ( that I've auditioned ) . MPP stands for "Metallized Polypropylene" . Motor-Run caps are found in AC circuits for large motors / such as HVAC systems . Ebay offers surplus motor-run caps on a pretty regular basis ( though never of the correct value to be of much use to the "plug & play" type .

- It's always worth a look around at Jeff Markwarts' website (http://home.earthlink.net/~jmarkwart/) to check out his recommendations on various topics . If you contact him, perhaps he'll rebuild your crossovers or ( most likely ) build you new updated types. He makes some recommendatons for manufacturers of the different parts found in a passive crossover .

>< cheers :)

[Marvin]

Thanks so much guys. I am very ignorant as to what I need to do to get my (846B) Altecs to perform as close original as I can. I really appreciate your input as to my dilemma. I have read some of the postings here and I must admit a lot of it is WAY over my head. I just remember listening to music from the 70's, closing my eyes, and I could just see the artists performing in my living room. I want to get that sensation back.

I know there is a speaker restoration company in Tampa Florida I have emailed that says they can refurbish my (846B) Altecs. They are call "The Speaker Exchange". I would hope anyone having dealings with this company would give me their opinion. I don't want to give my drivers and crossovers to just anyone. Like I said, I have had these speakers for 35 years. The cabinets are perfect. It's just the sound that is the problem.

Again, thanks for your comments. I am listening and I will take you advice seriously.
Marvin

[Earl K]

Hi Marvin,

- I don't know "The Speaker Exchange" (http://speakerex.com/) and haven't heard any mention of them ( that I can remember ) on the various forums ( good or bad ) .
- OTOH, if they ( Kathy I guess ) are promptly responding to emails that's better than you can expect from GPA ( who respond best to telephone calls /as goes the scuttle-butt ).
- I'd stay away from buying one of their premade crossover solutions for your 846B(s) . Stick with simple recapping .

- I'm still inclined to suggest that you hand over your drivers to GPA ( since they are the sole manufacturer for all the present-day replacement parts for Altec drivers ).
- GPA will also tell you whether or not it's true / if the 34647 diaphragm is actually available ( since they're the ones who can make it. I mention this because the web-page for the Speaker Exchange states the 34647 replacement diaphragm is NLA .
- Additionally, GPA will also recharge the magnet of your 806 drivers (remagnetize) when they install the new diaphragms ( as well as install the necessary diaphragm connector adapter kit that's needed because your older diaphragms have a different style of connector ).
- Take some pictures of the inside parts of your N800K crossovers . If the capacitors are accessible ( seen, after removing the Xover from the cabinet ) then I would recommend replacing the caps yourself ( or having someone local to you do this / like a local TV repair shop ) .
- It is really a simplistic matter for any person owning a soldering iron . You'd just need to source some replacement caps first / so they are on hand if / when you take it to a repair person .

- On a different matter, why are you blaming your speakers for the change in their sound ? ( It might be another component in your playback system has not aged gracefully / such as a preamp or amplifier ). What led you to this conclusion ?

>< cheers :)

[Marvin]

Earl,
I know one of the horns was blown and repaired (by me). Also the sticky substance on the accordion portion of one of the woofers has puddled at the bottom. I also believe after all this time the caps in the crossovers need replacing.

I have replaced the amps many times. The Altecs always sounded good. They still sound good, jest not as good as I remembered them. Also, one of the pots on the back has a dead spot.

I would like to pull all the components out and send them to a qualified technician for a thorough check out. Something I can't do, but feel needs to be done. I jest don't know who or where to send them. Your suggestions and comments are appreciated. I know I can count on the guys on the forum...
Thanks,
Mavin

[Earl K]

I have replaced the amps many times. The Altecs always sounded good. They still sound good, jest not as good as I remembered them. Also, one of the pots on the back has a dead spot.

- Okay, just checking that you've got the right culprit .


I would like to pull all the components out and send them to a qualified technician for a thorough check out. Something I can't do, but feel needs to be done. I jest don't know who or where to send them. Your suggestions and comments are appreciated. I know I can count on the guys on the forum...

- I suggest only entrusting GPA to do a full diagnostic of the 6 components // if you're dead-set on pulling & shipping all the parts .

- I would do this only after you've found a bullet-proof shipper ( & taught yourself bullet-proof packing / think ; "drop-tested" from 4 ft onto concrete as an adequate protection-test ) .

- Frankly, six shipped components / shipped both ways / can only end in tears & frustration ( I fear ) .

- Holding out till you find someone qualified for the diagnostic work / that's also within a drivable distance / is the only sane approach to avoid calamity ( IMHO ) .

sorry for the dark clouds >< :(

[Marvin]

No apology necessary Earl,
This is the kind of advice I was looking for. I will pursue this situation with much caution.
Thanks

[Marvin]

Sheese, If you read what GPA disscribes about packaging, I might as well carry my speakers to them personally. Ha, only kidding. My speakers are like gold so I can appreciate where they are coming from. You can't be TOO careful.

I have read on the forum where some members are substituting components to try to improve the performance of their speakers. I wonder if this is wise?

To try to improve means to change the sound quality. Is changing the sound really a wise choice? If you change the crossover, the HF driver, or the LF driver what are you accomplishing? I for one would like to know. Is the average person MORE knowledgeable about the quality of audio reproduction than the engineers at Altec?

I would think if the exact components were not available for these speakers, than components that closely resemble there performance would be the preferable replacement. What am I missing here? I don't want someone to tell me that "IN THEIR OPINION" this component or that component is "BETTER" than the original without some facts to back it up. In my humble opinion, the original is still the best. Like original vinyl recordings, tube amplifiers, and Altec speakers. Please enlighten me. With all the modern technology, sometimes the old stuff is still the best.

I'm not trying to put you down, just trying to understand your thinking.
Thanks for your contribution,
Marvin

[sonofagun]

Speaker Exchange will do a fine job on the drivers.

I make 846B replacement foam grilles.

[Marvin]

I talked to GPA who is the authorized Altec repair facility and they informed me thay can do all the necessary work on the drivers. HOWEVER, they do not rework or repair the crossovers. They suggested I consult the knowledgeable people on the forum for advice as to the best components to refurbish my original crossovers.

So, HELP! As a former Dinosaur computer tech, I feel comfortable in replacing the various components. I just would like advice on what to replace and where to obtain the said components. Is there a kit maybe, or a list of parts needed. GPA also said the components made today are superior the the original ones. I think I remember seeing a schematic somewhere in the forum. Although not necessary, I'm sure it would be helpful also.
Thanks for all the help,
Marvin

[Earl K]

They suggested I consult the knowledgeable people on the forum for advice as to the best components to refurbish my original crossovers.

So, HELP! As a former Dinosaur computer tech, I feel comfortable in replacing the various components. I just would like advice on what to replace and where to obtain the said components. Is there a kit maybe, or a list of parts needed. GPA also said the components made today are superior the the original ones. I think I remember seeing a schematic somewhere in the forum. Although not necessary, I'm sure it would be helpful also.
Thanks for all the help,

- Wait until you get back your refurbished drivers ( from GPA I assume ) before doing any crossover mods . Give the system a listen for a couple of weeks before deciding your next step .

- This way ( taking a step by step approach ) you'll be able to track what mods lead to what sonic changes & whether or not you actually like them .

- Don't be naive and just assume that "better or more modern" ( according to GPA ) means you'll like it .

- Parts Express (http://www.parts-express.com/home.cfm?CFID=6337260&CFTOKEN=66545326) will be a valuable source of parts for your crossover rebuild .

>< cheers :)

[Zilch]

There's two caps in it. Let's pretend it's some kinda big deal:

[Marvin]

Are the capacitors the only thing I need to replace? How about the transformers? I believe I have a good source for the components. I don't want to overlook something and wonder later on if I should have done more.

I apologize if I ask too many questions, but this is really kind of a big deal for me. My knowledge is very limited and I want to do this right. I don't want to take any shortcuts that might bite me in the ass later on. Been there, done that...

Thanks for your patience,
Marvin

[Earl K]

Marvin,

- Those transformer "look-a-likes" are inductors ( or sometimes just called "coils" by some people / like myself ) .

- Anyway, read this thread about updating the passive components in the (Altec) Model 19 crossover. (http://www.audioheritage.org/vbulletin/showthread.php?p=138383&highlight=L220+internal+volume#post138383)

- The "read" will give you an idea about some of the sonic changes that'll occur when you swap out the passive components found in a crossover .

- While your woofs and drivers are away for checking & possible refurbishment by GPA , I suggest you ponder the question about if you really want to upgrade or change the systems' sonics ( by swapping out the passive components in your crossover ).

>< cheers :)

[Marvin]

Thanks Earl,
Again I show my ignorance. I truly appreciate the education I am getting. I hope it will improve my restoration project as well as save me some money.

The inductors as well as the caps are covered with a light coating of mold due to storage for a time. I don't know if that will effect the composition of materials to the point of effecting the sound. Thats one reason for contemplating replacement.
I stopped by a local audio shop yesterday. The 2 guys there, who looked like they were right out of the 60's, questioned why I wanted to do ANYTHING to my Valencias. They said the crossovers were probably fine. I have always heard the caps will leak over time. The HF driver was also probably OK. Although I know one was overdriven to the point where one of the wire connectors to the diaphragm was burned into. I repaired that myself, but noticed the diaphragm itself was discolored from the heat. I feel sure that could effect the sound.
They said they could recone the LF driver which has the sticky substance puddling in the bottom. I thought I would call GPA and get their opinion, but I wonder if they (GPA) would tell me what I need to do without money involved. I plan on spending the cash for the restoration, but my concern is I don't want to do something I will regret later. I thought I would take my parts to the local shop, but under the circumstances I don't know if I trust their opinion.
I wonder just how much of the internals NEEDS to be repaired or replaced. I value the opinions expressed here on the forum as I believe there are many that have gone through this same situation. I also understand the HF driver GPA sells is superior to the original 806-8A's. I believe it is a 902. I am still doing research. One thing is for sure, this restoration is going to cost as much as the speakers did originally.
Anyway, thanks again for you patience and information. I hope there are others reading this than can benefit from all the knowledge or in my case the lack of...
Marvin

[Earl K]

Hi Marvin,

- Puddling of the surround goop doesn't necessitate a recone .
- I wouldn't trust someone ( to do any work on my stuff ) who thinks otherwise.

- A rubbing/burnt voice-coil ( or torn cone ) does require a recone / but not puddled goop ( IMO ). The goop has migrated there because of gravity & heat ( over the course of time ) .
- Others here have sucessfully used a controllable heat-source ( such as a hair-dryer ) to soften up the goop / & then either remove it / or respread it ( with a tiny scoop-spoon , as a for instance ) .

>< cheers :)

[Earl K]

I thought I would call GPA and get their opinion, but I wonder if they (GPA) would tell me what I need to do without money involved. I plan on spending the cash for the restoration, but my concern is I don't want to do something I will regret later. I thought I would take my parts to the local shop, but under the circumstances I don't know if I trust their opinion.

- I would ask GPA if they think that puddled goop warrants a recone .
- Suggest to them that you'll respread the stuff or remove it before sending the woofs in ( if GPA won't do it for you ).
- GPA will recharge the alnico magnets in your woofers ( and compression drivers ) for a fee . A local shop just doesn't have that capacity ( even if they are trustworthy ) .

>< cheers :)

[robertbartsch]

I've sent a few items to GPA for repair and they are very good.

....you should work in pairs. I would recommend doing both compression drivers first and then both woofers, if necessary.

Often when people say their system lacks the zing it had when new, the diaphragms in the compression drivers have become old and tired.

As far as not being able to buy diaphragms because Altec is gone, GPA acquired the original tooling used to manufacture these systems.

...as far as the replacing caps go, this seems like something you might be able to tackle at home.

[Marvin]

Thanks guys, Good discussion.
I called GPA today. They told me to apply Acetone to the sticky surround on the LF driver to soften it up. I did and eventually I did remove the puddling. They gave me some interesting information. They said the LF (woofer) driver should be rotated 180 degrees to prevent the puddling in the future. Also, if the caps in the crossover were not bulging, they were probably OK and would not need replacing. The inductors should be fine. My HF pot is vented, so I could spray in some contact cleaner, work the pot and clean it. The only thing I really needed to send them was the HF driver. I asked them to replace the diaphragm and re magnetize it. This was mainly because one driver had been overdriven and blown out. They said my repair was probably OK but, would probably go out again unless it was restored with the updated design. The cost of the repair should be about $200 for everything.
I hope this helps someone else as much as it has helped me. Thanks to all for your comments...
Marvin

[robertbartsch]

So it is $200 to re-mag one driver and replace the frame?

[Marvin]

No, sorry for the confusion. I was quoted $90.40 to replace the diaphragm and re magnetize one driver. Two HF drivers then would be $180.80. I shipped UPS ground with $500 insurance for $32.86. SO, my total cost is $213.66. I just was making an approximation.

The guy I talked to at GPA was very helpful and saved me from doing more than I needed to. That is something you don't see everyday. Packaging is very important. Use plenty of bubble wrap.

I'll post an update when I get the drivers back.
Thanks,
Marvin

[Earl K]

No, sorry for the confusion. I was quoted $90.40 to replace the diaphragm and re magnetize one driver. Two HF drivers then would be $180.80. I shipped UPS ground with $500 insurance for $32.86. SO, my total cost is $213.66. I just was making an approximation.

The guy I talked to at GPA was very helpful and saved me from doing more than I needed to. That is something you don't see everyday. Packaging is very important. Use plenty of bubble wrap.

I'll post an update when I get the drivers back.
Thanks,
Marvin

- I'll be looking forward to your update ( once you've got those drivers back in the speakers ).
- Then, if you feel more refurbishing is required , we can revisit the topic about a crossover tweak ( or two ) .

>< cheers :)

[Marvin]

I'm supposed to get my HF drivers back tomorrow so I'll give an update then.
In the meantime I thought I would pose a question about leaking capacitors. I asked an audio tech awhile back about leaking capacitors in my crossovers. He said if they were not bulging they were OK. Well that's not exactly what I understand about leaking capacitors. I always thought capacitors leak over time. Meaning they allow the audio frequencies that they are supposed to filter out to overlap. The material inside that the capacitor is made of, I believe it is called the "dielectric", can brake down over time allowing frequencies to "leak" that they were supposed to trap. This causes both drivers in a two way system to reproduce frequencies they were not intended to receive. This makes for inefficient sound reproduction. Does this make sense? Anyway, this is what I understand is the purpose of the crossover and the term "leaking" capacitors.
Help me out here guys. Audio theory is not my strong point.

[Marvin]

I have my drivers back and installed. Speakers sound pretty good, but I understand they could sound better. After talking to Ron though I might just leave them as is (original) and build another set of speakers with up graded components. How about a set of high end quality A7's. Hummmmm....

[Antonio]

I have my drivers back and installed. Speakers sound pretty good, but I understand they could sound better. After talking to Ron though I might just leave them as is (original) and build another set of speakers with up graded components. How about a set of high end quality A7's. Hummmmm....

Hi Marvin,
I have been following this very interesting thread (mainly because I own the same pair of speakers than you do). I can almost 100% agree with the advices and the path that Earl K has been suggesting to you. In my opinion he describes a very carefull and "based on facts" aproach to the term "restoration" and which company or opinion to trust.
Now my opinion :blah: (everyboby has his own :)):
1. If the caps of the x-overs are realy of the dry-paper/waxed-alu-foil-types then it is very unikely that they will leak. From my understanding only wet (e-lytic, pio's, tar(!) etc.) can leak over (long) time. So, keep 'em in! Anyway, if you decide not so, take care while removing the caps from their fixing springs, they are hold very strongly by those black "springs": when I tried to move one out, the outer tubular cylinder broke into pieces (the cap is still working and having the original value of 8µm!!). Just to be sure and to avoid having to open the speakers and x-over box again in the future I replaced it with two paralleled NOS Siemens MKL Caps I have around and couldn't hear any difference.
2. Don't spray contact spray into the attenuator, but open it instead and carefully clean it with a cotton stick an medical alcohol. Observe if the copper sliding contact is touching the pots wires at every point of its turn and carefully adjust if needed. The cover of the pot is kept in place with some "ears" bent around the bottom. You can carefully open these, remove the fixing nut and get the whole thing apart. Take care to exacly memorize how every part was fit together, because there is a spring loaded pot contact that will move everything apart once you loosen the fixing nuts. But don't worry it is easily remountabe, I did it! BTW, there is a japanee page in the web where some guy showes how he took the pots apart to clean them.
3. Keep the inductors as they are, they normaly do not age.
4. Keep the bass drivers as they are and follow GPA advice according turning them 180 degrees every some years.
5. If you blew your tweeters then they may need repair, which by itself (asuming you don't get the original diafragms or close copies) will change the sound. Therefor try to keep them as close as possible to the original. Replacing the tweeters by other or more extended types will change not only the frequency responce to a presumably "better" but also changes the complete sonic balance of the speaker. If you add frequency on the top you have to do so at the bottom (easily spoken) otherwise a well balanced speaker becomes unlistenable over time.

Anyway, in my opinion, and as I could read somewhere in this thread I am not alone with it, Altec Engineers may have had some special opinion why to use these drivers and these x-over components in this cabinet! If you liked the original sonics before, try to keep them original. "Modern" "boutique" components and different drivers will change the sonics of your Valencias. You may like it or you may not (in most cases you wil not know what the sonic result will be before), only one thing is for sure: this ain't a pair of Valencia's anymore then!

It is very difficult to remember what a speaker sounded like some years ago: you or your taste my have changed, the room may have been different (very, very important), the rest of the components may also have. I wouldn't blame the Valencias for sounding worse, maybe just your taste changed? But anyway, from my opinion the sonic pattern of a good HIFI component (and the Valencias are very good imho) discloses itself after a long term period. Maybe you think different about your Val's in a few months.

Have fun, Antonio

PS: If you still have the original foam grilles or parts of them, I would appreciate alot if you carefully take the complete and exact measures of them (or from what is left). These are not longer available and exact dimensions are needed for reconstruction.

[Marvin]

I thought I would add a quick response here after listening to my repaired 846B Valencias. GPA repaired and recharged them (the HF 802's). A little over $200. They sound as good as new, or as close as I can remember. This place (GPA) is a joy to work with. Bill is the man. An honest straight shooter. He saved me much money advising me on what I needed or did not need for my restoration. I would highly recommend them and if needed, I would not hesitate to use them again.

The foam grills disintegrated years ago, so I have replaced them with acoustic cloth. GPA replaced my diaphragms with NOS ones they had so my Valencias still retain the original tonal quality. The crossovers were not altered. The sticky surround was refreshed by brushing with acetone as per Bill at GPAs instruction. I also spun the LF 416's 180 degrees. With a little lemon oil on the walnut cabinets and the Valencias are like new. By the way someone posted here that can reproduce the foam grills if you want them. I may look into that at some point if I can tear myself away from listening long enough.
Ahhh, life is good.....