Hafler amp problems

[still4given]

I hope it is OK to ask this here. I'm using Hafler power amps right now. I've got two of them not working properly. Took one in to a tech and he told me the power transformer was bad and that they were NLA. I paid him for his diagnosis and took the amp home. I measured DC voltage across the two big caps and I get 67v+ on the one side and 42v- on the other. The other P230 reads 42v+ and 42v- on it's two caps. So, thinking he is right I search around and find a guy (soundvalves) who has two NOS power trannies. Great! I buy them. I get them yesterday and proceed to install one. Get it all installed and power up and measure voltage. No change. SO now I start unhooking things and take measurements on my good amp and the one I've just installed the tranny in. I've got 47VAC coming out of both leads on the tranny on the P230. 44VAC on each lead of My DH-200 which is in working condition. I check the DC voltage coming out of the bridge rectifier and I'm getting 67VDC+ and 44VDC- on the P230. The DH-200 read 60VDC+ and 60VDC-. Could it be my bridge rectifier? My other P230 reads about 44VDC+ and 44VDC-. Is this a common place for things to go bad?
Thanks, Terry

[Norbert]

Hi Terry,

what is your P230 rated? So far I don't know this model. But what I get from your description is that the positive voltage rail is much too high (more than 20 Volts!). What are the offset voltages at the outputs of the bad P230? Does it change when you connect a dummy load (e.g. 8Ohm resisitor) Do you have a schematic?

Regards,

Norbert

[PSS AUDIO]

Originally posted by still4given
... I've got 47VAC coming out of both leads on the tranny on the P230. 44VAC on each lead of My DH-200 which is in working condition. I check the DC voltage coming out of the bridge rectifier and I'm getting 67VDC+ and 44VDC- on the P230. The DH-200 read 60VDC+ and 60VDC-. Could it be my bridge rectifier? My other P230 reads about 44VDC+ and 44VDC-. Is this a common place for things to go bad?
Thanks, Terry

Hi,

It seems that you have a bridge problem as 44AC goes for 66DC DC=ACx1.414)!

[still4given]

Thanks you guys, you're the best!

I'll look for one on Monday. Man, I just spent $140 on two trannies on the word of that tech. Gotta pay to learn I suppose. Maybe I can sell the one I didn't install.

Blessings, Terry

[PSS AUDIO]

Originally posted by still4given
Thanks you guys, you're the best!

I'll look for one on Monday. Man, I just spent $140 on two trannies on the word of that tech. Gotta pay to learn I suppose. Maybe I can sell the one I didn't install.

Blessings, Terry

What kind of a bridge is it?

A moulded one, or made of 4 diodes?

Whatever, I can provide you those parts if you have troubles getting them.

[Alex Lancaster]

Terry:

Look up part # 050-060 at partsexpress, 400V, 25A, $2.50.

[still4given]

Hi guys,

I believe it what would be called moulded. It says KBPC2502 on the side of it.

You can see the specs here. (http://www.pkfmars.ru/pdfs/KBPC10.pdf)

Since it appears that both amps have the same problem, I 'm wondering if I should maybe replace it with something better. Any suggestions?

Thanks, Terry

[johnaec]

Originally posted by still4given
Since it appears that both amps have the same problem, I 'm wondering if I should maybe replace it with something better. Any suggestions?If you lke Haflers, there are quite a few on eBay.

John

[still4given]

Hi John,

Yes I know there are a few Haflers on ebay. I keep my eyes open there for them.

I don't think I worded that right. I'm wondering about replacing the bridge rectifier with something else, not the amp. I would love to get these working again. I have found the stock rectifiers but I'm thinking, since I aready have two amps with blown retifiers, that maybe they are not the best design for this amp. Just thought maybe someone knew of something better to put in there, rather than the original designed bridge rectifier.

Blessings, Terry

[Alex Lancaster]

Terry:

Are You sure the rectifiers are blown?

If so, You might have a short circuit down the road, rectifiers don´t blow that easy.

[still4given]

Originally posted by Alex Lancaster
Terry:

Are You sure the rectifiers are blown?

If so, You might have a short circuit down the road, rectifiers don´t blow that easy.

Hi Alex,

No, I'm not sure. I really don't know much about electronics, but am trying to learn. I started digging deeper, when replacing the Power tranny didn't work. I do know that I get the same reading from the output terminals of the bridge rectifiers whether they are hooked up to the rest of the circuit or not. In other words, if I disconnect the wires from the output of the rectifier, it reads the same DC voltage as if it is connected. My logic tells me that if there was something shorted I should at least see some difference in voltage.

It bothers me that I paid a repairman to check out my amp, and he told me that the problem was the power tranny. I now know that is was fairly simple to check the output of the tranny and see that it was OK. The output from the bridge rectifier is what is low. Just seems he should have checked tranny by itself. He told me he couldn't fix the amp because the trannies were NLA. It took a bit of searching for me to locate some and so when I did, I bought them because they are hard to find and not being made any longer.

Anyway, the bridge rectifiers are inexpensive so it seems like it will be worth a try at least. If that doesn't fix it, I suppose I'll have to find another repairman to look at them. It's getting to the point now that I could have bought something else with the money this is costing me, but I am learning some things so I am going to try and stick it out.

Blessings, Terry

[Alex Lancaster]

As You say, the rectifiers are cheap, that Pexpress has more capacity than You need, and for $2.50, what the heck; when You put them in try them without connecting the output, if OK, hook them up and see if they overheat, You shoud be able to touch the heat sink and not burn Your finger, if You smoke them, the problem is possibly a shorted output (power) transistor.

Good techs are hard to find anywhere in the world.

Good luck!

[still4given]

Is there an easy way to tell if an output transistor is shorted out? Can I check it with a multimeter?

I think I can still get some NOS MOSFETs from the same guy I bought the trannies from. Hitachi doesn't make them anymore. There is a manufacturer in England who is making replacements.

Blessings, Terry

[Alex Lancaster]

Terry:

I think You need another tech.

[Zilch]

Click the multimeter over to AC volts to measure the ripple at the bridge rectifier output.

Oscilloscope will show you what's actually going on with the rectification/filtering.

If the DC output is low, either it's not delivering, or something is loading it down. Remember that transformers have impedance. Heavier load = lower output voltage.

If the rectifier is OK but hot, it's load. The culprit is likely to be overly warm, too, unless it's shorted.

Buyin' stuff and subsistuting is not the answer. Follow the current path to the problem....

[still4given]

OK, here's what I found. I changed out the bridge rectifier. When I installed it, I left off the output wires so I could get a reading on it with no load. The VAC coming from the transformer is 47.4 on both sides. The output from the rectifier is 19.5VAC and 42.3VDC each side. When I connect the wires to the outputs but with the wires disconnected from the Large Can capacitors. I get 44VDC+ on the + side and 43.9VDC- on the minus side. Then, when I bold down the wires to the Caps I get 67VDC+ and 44VDC-. Are the can capacitors designed to raise the voltage? My DH-200 reads 60VDC on both sides. Maybe the caps are bad.


One MOSFET seems to get warmer than the rest so maybe it is bad. I don't know how to check them.

Anyway, I would think that if there was a short downstream that I would see a big difference when i connected it, but I don't.

The amp has a buzzing sound when hooked up to speakers. It plays but distorted. When I hook up the Positive cab I also get a low hum. It doesn't really sound different whether I have the big caps hooked up or not. Make me think there is something wrong wit the caps.

Wish I had a good tech around. It's obvious the this one didn't know what was wrong with the amp.

Any more help you guys can muster will be greatly appreciated.

Blessings, Terry

[Zilch]

I trust you know you are working with potentially lethal voltages here. 60 VDC is considered dangerous, albeit not terribly so. Don't short out those capacitors with your tongue.... :biting:

The 19.5 VAC you read coming out of the bridge before you connect it to the filter capacitors (cans) is the "ripple" your meter is reading, over and above the 44 Volts it reads as the unfiltered DC. Note that your meter is not designed to read the unfiltered DC it is seeing there, so the readings are only approximate. Once attached to the filter capacitors, the filtered DC will approach the sum of the two, i.e. 64 volts (or more, apparently, in your case,) as the capacitors do their "job" of accumulating and storing the energy.

You want to measure the VAC remaining with the bridge output connected to the capacitors. I am guessing that you'll find hardly any on the 67VDC+ side, but the same 19.5VAC on the 44VDC- side, indicating that either a) the filter capacitor on that side is not working, or b) something is substantially loading down that side. The hum (60 Hz?) in the speakers indicates that the power supply filtering is not working.

So, confirm the VAC measurements on the filtered supplies, and if as above, I'd bet you need to replace that capacitor. I'd replace them both with identicals, if available, probably. Read the manufacturer, type and values and inquire here for substitutes, if necessary. Provide dimensions and pics, as well. Can you still get parts from the manufacturer?

Does anybody believe I'm giving bad advice here? If so, don't be shy; jump aboard! We don't want to smoke this amp.... ;)

[still4given]

Alright! :thmbsup: Now we're getting somewhere. I have two of these amps. The other one is reading only 44VDC or so on both sides. Like I said, there is almost no change whether the wires are attached the caps or not. My DH-200, which uses the same tranny, caps and bridge, is reading just over 60VDC per side and it plays perfectly.

Another thing I noticed is that when I attach the wires to the caps while playing there is a small arc on the cap that is putting out 67 VDC but none that I can see when connecting any of the other three, that are putting out the 44VDC or so. So does this sound like bad caps? I'm not sure if Hafler still makes these or not , I will check. I'll try to take some pics and post them and see if I can read writing on the side of the caps.

I can't tell you how much I appreciate this. Not just because I want to get my amp working, but I realy feel like I starting to grasp what is going on in here.

[still4given]

OK, I did some acurate measurments. Here they are;

Right cap> 65.3VDC, 0.0VAC
Left cap> 42.6VDC, 19.8VAC

Looks like you pegged it.

The cap reads;

EL CAP
CER 103
+10000MFD 75VDC
85C USA 8839

http://img.photobucket.com/albums/v357/still4given/4813f83a.jpg

http://img.photobucket.com/albums/v357/still4given/6809283b.jpg

Blessings, Terry

[Zilch]

Originally posted by still4given
Another thing I noticed is that when I attach the wires to the caps while playing there is a small arc on the cap that is putting out 67 VDC but none that I can see when connecting any of the other three, that are putting out the 44VDC or so.That's because that capacitor is working. When you first touch the lead to it, it is uncharged. The little spark is because it's taking in energy to store.

Take the same VAC readings on the other amp, capacitors attached. I'm betting, if the problem is the same, you'll see the same ~20VAC ripple. That one hums too, and plays distorted? [You ain't usin' nice JBL's to test with, I trust....] :rolleyes:

Now, we gotta find replacement capacitors. What's holdin' them caps in there, just the strap going from + to - on them in the middle? You want the same capacitors, physically, so they fit in the same space. Check Parts Express, Hafler Service, Google. Similars seem to be around $20. I've found Sprague @ 2" X 4.25" and Mallory @ 2" X 3.125" or 4.125" no El Caps, tho, yet....

Here, for example. (http://www.mouser.com/index.cfm?&handler=data.listcategory&Ne=100&terms=75V+10000uf&Ntt=*75V*%2b*10000uf*&Ns=MfgrPartNumber%7c%7cSField&N=294&crc=false)

Ummm, measure with a PLASTIC ruler. :D

Google says: Capacitor Address. - J. Kom-Tek, Division of El Cap. 116 Depot Street. Elgin, TX 78621-2614. USA. Tel: 512-285-5255. Fax: 512-285-5158. Type: Aluminum. If that's them, they can tell you who their distributors are, and whether they still make these particular ones.

Last line there is the date code, most likely. If so, yours were made in ithe 39th week of 1988, i.e., 16 years ago....

[Alex Lancaster]

OK Terry:

One of the caps is bad, but You should change both, You got the 10,000, the voltage and the 85 Celsius temp, or higher, any brand will do, but I would use new ones, if You get them cheap enough, check the voltage without connecting to the next stage, You should be getting +-60VDC and almost zero VAC; If You have 2 bad amps, try the 2 best caps on one amp, maybe You´ll get away with it; I don´t know the price of caps up there, but they can be expensive.

[still4given]

Now, we gotta find replacement capacitors. What's holdin' them caps in there, just the strap going from + to - on them in the middle?

They have a strap type cradle that they sit in. If you look closely at the picture you can see the band at the bottom. It would be best if I could find one the same diameter as the one that are in there. If not, maybe the company that make the replacement cap also make a cradle mount to fit.

I called the phone number fo Kom-tek. I got a disconnect recording.

Another question. Does it hurt to go up in value if I can't find the exact ones? Say, 11000mdf or 100V? Are these values important?



If You have 2 bad amps, try the 2 best caps on one amp, maybe You´ll get away with it; I don´t know the price of caps up there, but they can be expensive.

I thought of that but there is only one cap between the two amps that shows 60VDC. The others are all down around 40VDC.

Thanks for everything, I will measure when I get home and see if I can locate one that will work.

Blessings, Terry

[grumpy]

Another question. Does it hurt to go up in value if I can't find the exact ones? Say, 11000mdf or 100V? Are these values important?

10% difference in value is not important (electrolytics usually aren't that close to begin with).

Keep the voltage rating up though, to the mfg
value or higher or you could end up wearing
capacitor on your face (not good). Might keep
in mind that higher voltage ratings will typically
increase at least one dimension of the cap,
assuming similar design & construction.

Sounds like you're starting to have fun :D

-grumpy

[still4given]

Originally posted by grumpy
10% difference in value is not important (electrolytics usually aren't that close to begin with).

Keep the voltage rating up though, to the mfg
value or higher or you could end up wearing
capacitor on your face (not good). Might keep
in mind that higher voltage ratings will typically
increase at least one dimension of the cap,
assuming similar design & construction.

Sounds like you're starting to have fun :D

-grumpy

I am enjoying the learning experience. I could have done without the expense of two trannies I didn't need. :banghead:

I'm not sure what you mean by
Keep the voltage rating up though, to the mfg

Could you explain that a little better?

Thanks, Terry

[scott fitlin]

You can increase the cap as far as rated working voltage, but you cannot use a lower rated working voltage!

If your caps are 85vdc, you go with 85, or higher. 100vdc will be fine! I dont think you need to go substantially higher than a rated working voltage of 100vdc!

If you were to put a 65vdc cap in there, it could blow up! This is why you dont use a lower rated working voltage.

:)

[Zilch]

Your caps are rated 75 WVDC, 75 Volts DC Working Voltage. Seems your amps are actually using them between 65 and 70 VDC, which is fine.

BUT, if you buy replacements at, say, 63 or, worse, 50 Volt rating, to save a little money, they'll possibly blow up on you. Grumpy is cautioning you NOT to replace with capacitors having a lower voltage rating than 75 V. You could go higher, though, and get higher voltage rated caps, but those will likely be physically bigger and not fit.

Regarding the capacitance, I agree that going 10% to 25% higher would not be a problem, but, once again, the can will probably be bigger, and they'll cost more. I would NOT, however, jump up to 15,000 MFD or higher, I don't think, unless Hafler recommends it, as that might stress other components. Respect the designer's component selection unless you know it to be faulty.

[Zilch]

Originally posted by scott fitlin
If you were to put a 65vdc cap in there, it could blow up!The forum is unanimongus on this issue, coast to coast and Mexico included! [An apparent rarity here.... :D ]

Same thing will happen if you hook 'em up backwards, as well. Pay attention to the polarities, there....

Another point: I note in reviewing the specs on these "Computer Grade" electolytics (commercial rating 85° C) that their lifetime is stated as 10 years. Typically, they last much longer, though. I'm guessing your amps were either environmentally stressed or unused for a long period for these to fail like this.

I'm not familiar with El Cap, but both Mallory and Sprague (Vishay) are quality manufacturers. Mounding straps will likely come with the caps or are readily available.

This may be premature; we don't yet KNOW that the caps are the problem, or the only problem, for that matter, but it's sure looking to be a good bet at this point....

[scott fitlin]

Its entirely possible the big power supply electrolytics are somewhat dried out from both use and age!

If in fact the caps, or one of, is going bad, or just out of spec, I would replace them all!

An easy way to see how your caps are is to borrow a capacitance meter, and measure the value of the cap. If you measure a value more than the + - 10% spec, you need new caps!

However, at this point in time, not having the amp in my possesion, and from what I have read so far, I am not entirely sure the caps are the problem, or the entire problem!

The caps in your power supply can be gotten, Mallory, or Sprague are both good! Shouldnt be that expensive either!

If you were here, or close to NY, I would send you to my service center, they are crackerjacks, and could overhaul the entire amp for you!

[still4given]

Thanks for all the help guys! I ordered these. (http://www.mouser.com/index.cfm?&handler=data.listcategory&D=75-36DX103G075BC2A&terms=75-36DX103G075BC2A&Ntt=*7536DX103G075BC2A*&N=0&crc=true)

I am aware that this may not be the entire problem. I did feel one of the MOSFETs getting a little warmer than the rest. I guess I'll cross that bridge when I get to it.Do any of you know how I can test those transistors while I'm waiting? It there a way to test them with a multimeter? I wouldn't mind getting those ordered while I'm waiting for the caps, if I need them.

Thanks again, Terry

[Alex Lancaster]

WOW!, the Hafler Odissey!; Some inexpensive multimeters have a transistor checker, do You know anybody that knows how to use them?

[Figge]

Originally posted by still4given
Do any of you know how I can test those transistors while I'm waiting? It there a way to test them with a multimeter?


well simply set the multimeter on diode test and try how the transistor leads it should show around 500 when leading, then swap cables and there should be nutn, oneway lead. try on all 3 legs, (transistor chassi = 1 leg) in diffrent combinations. if the multimeter beebs = transistor shorted, however i dont think theres any problem with it, the fuse should keep blowing if so.


oh and when doing the test the transistor must be out of the circuit...

[still4given]

Shucks, I don't think my multimeter has a diode test on it. :hmm: Maybe time to upgrade.


Blessings, Terry

[Alex Lancaster]

Hey Terry: You are getting pretty enthused about electronics; If You´re going to buy a new multimeter, get one with a transistor checker and a frequency counter, You can spend a bunch of money, but try to get one on "special" from Radio Shack I´ve used them for years, maybe they even have one with a capacitor and inductor checker (which if You keep going, You will need),for about $100, next stop, an Oscilloscope, I guess.:thmbsup:

[Zilch]

Don't think I'd be probin' MosFETs with no multimeter. Nope....

See HERE (http://www.uoguelph.ca/~antoon/gadgets/mostest.htm)

And HERE (http://www.4qd.co.uk/serv/mostest.html)

A Pass Laboratories pdf with more than you wanted to know.... (http://www.passdiy.com/pdf/mos.pdf)

[scott fitlin]

Do yourself a favor, and find a good tech shop and have the amps repaired properly, or give Hafler a call, and send it to them for overhaul!

[still4given]

Originally posted by scott fitlin
Do yourself a favor, and find a good tech shop and have the amps repaired properly, or give Hafler a call, and send it to them for overhaul!

Hi Scott,

That's probably sound advice, however, I've been wanting to learn this stuff for a long time. I have almost no investment in these amps and to be honest, given the availability of parts, it really takes someone like myself, who is willing to hunt them down, to get one fixed. The tech I took the first one to, made a couple of calls and was told that the parts were NLA and that was as far as he was willing to go. I can buy these amps on ebay all day long for $150-$200. It would cost me more than that for a tech to source the parts and fix it and then I still wouldn't know any more than I do now. I really, really want to learn how to fix these things and this seems like a prime opportunity for me to do that. I can't help but think there are other folks here who are interested in this as well and may therefore be learning right along with me. I can't be sure of that, but it seems logical to me.


Zilch,

Thanks for the links. I have printed them out and will be reading up on this as I await the delivery of the caps I've ordered.

Blessings, Terry

[still4given]

Well the new caps arrived today. They seemed to do the trick. Both amps are playing now without any hum. They aren't quite as clear as I was hoping for. Not bad but they seem to distort at a lower gain that I thought they would. The biggest surprize was when I tried the caps in my Soundcraftsmen PCR-800. WOW! that amp really kicks. These caps are too tall to work in the PCR-800 so I have to get the right size but i am totally impressed with it right now. The bass authority is really nice.

Anyway, any tips for tuning up these Haflers? Maybe set the bias? If so, how do I go about that?

Since I have two, would I be better off strapping them and running one on each side?

Thanks for all your help. It's really good to have them running again.

Blessings, Terry

[Zilch]

Originally posted by still4given
Since I have two, would I be better off strapping them and running one on each side?
You KNOW the drill: if they're designed for bridging, strap them and make an "empirical determination." :D

If you want to dig deeper and "tune" them, you can't "wing" it like we did with the power supply filter caps. You need the schematics, owner's manual, and, preferably, the service manual. Read up and learn how they operate, and what adjustments (usually none) are available.

Experienced techs recognize analogous circuitry and design approaches within and among various genres of amps. The basics are the same in just about all of them, though. Schematic in hand, and with a little more equipment than you have (oscilloscope, signal generator,) you can follow the signal path through the circuitry and diagnose problems, if any, or at least confirm the product is performing according to specifications.

Hint: Your local repair guy (possibly even the one who told you wrong, here,) likely has a HUGE backlog of stuff he can't make the time to fix. Find the one who has racks full of stuff awaiting his attention. Volunteer to help him out on Saturdays, or whenever, so you can learn. You want "bench time," even if it's just changing line cords and replacing fuses to start. Once he's satisfed you're competent, he may "farm out" his overflow to you. Our local
vintage audio recycler (http://www.thesoundwell.com) has been doing that for 30 years here now. If you like this stuff, and develop your skills, it can serve you well into your retirement....

[still4given]

I have part of the manual and part of the schematics for this amp. Someone gave me step by step instructions how to set bias over at the DIYforum. I'm going to study that and see if it looks like something I want to tackle. It's more detailed than I expected.

I'll try strapping the amps tonight and see how they sound.

Thanks, Terry

[Ian Mackenzie]

Terry,

There have been previous Hafler mods in TAAS, write them for details.

But you can't make a silk purse out of a sour's ear.

They were always a bit harsh as I recall, but not bad for a 80 's mosfet amp. People would bypass the caps in the signal path hoping to re invent the amp. But it should a do nicely for bass.

If you really want heaven, do a search on diyaudio.com for an Aleph 5 or 60, easy to build. Absolutely no comparison with the Halfer genre.

Ian

[Mr. Widget]

Originally posted by Ian Mackenzie

But it should a do nicely for bass.



Years ago I had one of the DH200s. I did the Mod Squad thing to it and ended up using it as a bass amp. I was quite happy with it in that application.

These days I have a Hafler P3000 and a pair of 9505s. They are not Aleph league, but are not slouches either.

Widget

[still4given]

Originally posted by Ian Mackenzie
Terry,

There have been previous Hafler mods in TAAS, write them for details.

But you can't make a silk purse out of a sour's ear.

They were always a bit harsh as I recall, but not bad for a 80 's mosfet amp. People would bypass the caps in the signal path hoping to re invent the amp. But it should a do nicely for bass.

If you really want heaven, do a search on diyaudio.com for an Aleph 5 or 60, easy to build. Absolutely no comparison with the Halfer genre.

Ian

Hi Ian,

Thanks for the advice. May I ask who TAAS is and how can I get a hold of them?

I am noticing a bit of harshness. I thought it was because something is out of adjustment. Maybe it's just the sound of the Hafler. I will mess with it a bit again tonight. I only had a few minutes last night and tried strapping them. I got some weird kinda phasing issues. I didn't have time at all to play with any. I goint to try switching wires around and see if it goes away.

Mr Widget,

What is the "Mod squad" thing. Did it make much difference? If I can't get these to sound clearer in the high end, they may get relegated to driving subs of PA speakers.

Blessings, Terry

[Mr. Widget]

Originally posted by still4given

Mr Widget,

What is the "Mod squad" thing. Did it make much difference? If I can't get these to sound clearer in the high end, they may get relegated to driving subs of PA speakers.

The Mod Squad were (perhaps still are?) a group that sold modification kits and performed modifications on popular audio products. The kit I bought was primarily a bunch of bypass caps. There may have been a few other tricks, but I certainly can't remember now. As for improvement? Well I built my DH200 from a kit (David Hafler, the founder of Dynaco, was trying to do it again in the 70's with kit amps and preamps but eventually only sold built amps.) and I installed the Mod Squad kit during the initial assembly so I had no point of comparison. I only kept the amp for a couple of years.

Widget

[boputnam]

"The grooviest gang of fuzz who ever wore a badge..."

Sorry - someone had to do it, and I needed to beat Giskard to it!

:rotfl:

[still4given]

Originally posted by boputnam
"The grooviest gang of fuzz who ever wore a badge..."

Sorry - someone had to do it, and I needed to beat Giskard to it!

:rotfl:

:D :rotfl: :rotfl: :thmbsup:

[scott fitlin]

Originally posted by boputnam
"The grooviest gang of fuzz who ever wore a badge..."

Sorry - someone had to do it, and I needed to beat Giskard to it!

:rotfl: Very good.

Thanks, Link! :D

[Ian Mackenzie]

Terry,

TAA is The Audio Amateur, now know as Audio Express if yo do a www search.

I know its fun playing around for older amps, I did it for several years during my JBL re incarnation, Phase Linears and various other boat anchors...the front panels were the best part of the design.

Years ago I recall a local dealer called Penny Lane Audio pushing highly mod's Hafler 220's to driver Sonab speakers.

They were a high impact amp, good if you like to play it loud.

Ian