Carver Amp Issues :(

Airplay355

I think the right channel on my carver is starting to die. It's sending our a garbled (that's the best way I can think of to describe it) signal. I checked to make sure no drivers are blown and everything is kosher there. I tried using a different set of preouts and a different set of inputs in the pre and that didn't help either.

Is there any way I can pop the hood and check to see if something is broken? What would be making a garbled sound and can I have it fixed? The amp is cosmetically perfect so it would be a shame to lose such a nice amp just because a channel fizzled out.

thuffman03

Most likely needs some servicing. Bob Carver and Rita Helms opened up a shop to repair Carver and Sunfire products. Here is the link off of the Carver web site.

http://www.carveraudio.com/phpBB3/viewtopic.php?f=4&t=7093

thsmith

My TFM-55x is behaving the same way but I am sending my to Rolland at carveraudio.com

heiney9

Parts............especially caps wear out and need repair. Avg life expectency for an electrolytic cap is 7-10 years. If you like the amp take it/send it for repair. I had a 1986 pre-amp that need repair. It cost me $102 to have a 2 caps replaced and it was well worth it.

engtaz

thuffman03 wrote: »

Most likely needs some servicing. Bob Carver and Rita Helms opened up a shop to repair Carver and Sunfire products. Here is the link off of the Carver web site.

http://www.carveraudio.com/phpBB3/viewtopic.php?f=4&t=7093

+1 sending to Bob and Rita's shop. Very good service and prices to boot.

amulford

Here Here...

Airplay355

**** if it's $175 + shipping to get it fixed I think it may be totalled. I only bought the amp for $225 (shipping included).

treitz3

What kind of amplifier do you have? Also, have you tried Caig De-Oxit on the connectors?

thuffman03

For smaller wpc amps it is an expense. I have a TFM 55 that I am sending to get fixed soon. It makes sence for me to send that one back do to the fact it is worth more.

If you really enjoyed the amp I would recomend sending it in for repair. It will then be able to give you years of enjoyment.

sucks2beme

Re-capping is a reality for most owners of classic amps.
Buying another classic Carver is just another ticking time
bomb. Get it re-capped and enjoy it another 20 years.
If you like the amp and know it's good, why not? Another
amp might not sound as good.

Airplay355

True. How hard is re-capping the amp for someone who doesn't know amplifiers? I figured I'd ask my physics teacher about it since 1) he's a friggen genius and 2) he likes fixing stuff.

Do you really need to have a lot of experience with recapping to be able to do it or could someone who has the schematic and a know how of electronics fix it?

Also, is there any way to definitely know it's the caps? Could it be something harder/more complicated to fix?

treitz3

treitz3 wrote: »

What kind of amplifier do you have? Also, have you tried Caig De-Oxit on the connectors?

Answer this first and I can help you a little bit more.....

sucks2beme

Airplay355 wrote: »

True. How hard is re-capping the amp for someone who doesn't know amplifiers? I figured I'd ask my physics teacher about it since 1) he's a friggen genius and 2) he likes fixing stuff.

Do you really need to have a lot of experience with recapping to be able to do it or could someone who has the schematic and a know how of electronics fix it?

Also, is there any way to definitely know it's the caps? Could it be something harder/more complicated to fix?

No, there's no way to be sure without checking. And that's the rub. 90%
of the work is finding the cause. Fixing (if the parts are still out there)
is the easy part. The caps are quite often the cause of the problem, but often take out a lot more stuff. Clean the controls first, then check it out.
Next step: find an upperclassman EE and buy him some beer. Have him find and fix the problem. And if he's up for it, get him to change out the electrolytic caps. Note: make sure he's not consuming the beer while
working on the amp!

Airplay355

Ahh sorry treitz I appreciate your offer, I just missed your post. It's a carver m0.5t. One of the silvery magnetic field amps. I got it from a member on the forum. Now that I think of it, it could be a binding post issue. I remember one channel had a plastic piece broken off (the only flaw). I'll pop the hood later tonight and maybe snap some pics if there's something I think is obviously damaged. I have not tried deoxit on the connectors. Again, really sorry about missing your post.

Sucks2beme, I'll check it out and talk with a few engineers I know.

Thanks for the help guys!

Airplay355

I couldn't find anything obviously wrong so I dunno. Could be anything

jcaut

I think I must be the one that sold you that 0.5t. I'm sorry to hear you're having trouble with it. I got it from TroyD. I think he had it doing center-channel duty in a home theater and I barely used it in the time I had it, so it's had a pretty easy life and is, IIRC, a very nice-looking example. Unfortunately though, like everyone mentioned above, those amps are getting to the age where they're gonna be needing some service. While the best bet would be to send it to one of the reputable Carver repair shops, it's possible that it's something easy that could be fixed by an independent shop or a capable DIY.

I'm not real familiar with many of the Carver amps, but I've done some work on the m4.0t/TFM4.0/42/45 amps. I believe that the 0.5t is basically just the "baby" version of the Magnetic Field design. Does it clean up somewhat at higher volumes or get more distorted? If it's more distorted at low volumes and then cleans up somewhat as you turn it up, it could just be a bias issue. That would still require someone with some knowledge to look at it, but parts cost would be low or possibly nothing. I'm just guessing...really could be just about anything.

If you choose not to repair, I believe an amp like that, "functioning, but with issues" would still bring a nice price on e-bay or similar sites.

Airplay355

My physics teachers have offered to attempt a repair. Dose anyone know what type of parts I should be buying and where I could possibly find a schematic?

I took physics but it was just a brief overview. I'm a pre-med major so I don't know much about the parts I'll need.

Ricardo

Well, physics is not equal to electronics......make sure he knows what he's doing.

I second the $175 option with the Carver shop. Yes, you would double the cost of the amp, but if you like it, you'd have a new amp that will last forever.

gdb

I'll also add.....A LOT of otherwise good electronic techs that were unfamiliar with Carver technology, have turned a large number of easily repaired amps....into paperweights,doorstops, boat anchors etc. RichP at the site linked below can let you in on the pitfalls to be avoided!;)


http://thecarversite.com/yetanotherforum/default.aspx?g=forum

Airplay355

I'm confident he is capable of understanding what's going on inside the amp. It's already unusable as is (except as a center channel amp maybe, but I don't have an HT) so if somehow it gets a little more messed up, then I'll just end up getting a new amp. There's no reason for me to spend at least $200 on this particular amp to get it fixed by Bob. I don't find it THAT special.

engtaz

Part of the posting of Carver sites is for you to go there and ask questions. Some of members are very good techs and can tell you what the problem is or what to look for. I have seen some help people from other countries, with troubleshooting their amps.

Airplay355

I sent Rich a PM. Hopefully he can help

jerryj12

Here you go.
Rita's Vintage Audio Repair

1920 Bickford Ave.

Snohomish, WA 98290

360-568-4700

Our Charges:

$175.00 Flat Fee

$175.00 for active drivers ONLY if it needs it

$75.00 for passive drivers ONLY if it needs it

$75.00 for tech labor time on unit over 3hrs.

$ 20.00 ONLY IF box & packing material are needed or wanted.

Customer pays Shipping & Handling both ways.

Airplay355

Somebody didn't read the thread...

Thanks anyway! lol

Airplay355

Got a chance to do some more listening. I switched from left to right with the balance knob and the left (busted) channel sounds like there's pillow over the speaker. The highs are there, just severely muffled. Sometimes the bass is also gurgly, that's the only way I can describe it. I though I had blown woofers at first, then I thought I was having tweeter issues because of the highs being f'ed but now I know it's definitely the amp. Very disappointing, there isn't oneworthy stereo in the house now

Airplay355

So Rich told me to take some readings using a multimeter do see if some of the settings in the amp are causing issues.

I bought a cheap analog multimeter but I'm not sure if I need to take these readings with the amp powered on or while it's unplugged. I've never used a multimeter before.

Also, how do I tell the difference between the anode and cathode on the little voltage adjust parts?

disneyjoe7

Using the diode setting on the multimeter, look for .7 +/- .1 or so on each diode, and transistor. It doesn't matter as to anode or cathode as you what the .7 voltage one way vs. open (more or less) remember you're checking components while in circuit.

Airplay355

Thanks Disney but I don't have a clue as to what that means. I set the meter to the DCV 500 setting and placed a lead on each side of the small black thing I was told to measure. I got a reading but it was far off from what I thought I'd get so I'm guessing either this thing is f'ed or I'm doing it wrong.

disneyjoe7

Wrong setting, but before we get into that... What's the make and model of this meter, so I can see the dial?

Airplay355

It's a gardner bender gmt-312. It was the cheapest one at Lowes. I hope it will work for what I need.

The dial says (clockwise) Off, 10,50,250,500 under DCV. It also says CATII 500V above those settings.

500, 250, 50, 10 under ACV.

250,50,0.5 under DC mA.

The last setting is OHM X1K.

disneyjoe7

Sorry for the late response, I feel I should post something.....


But you're kidding right? That meter is just electrical not electronics. You're playing with the amp right? I sure you can't fix that amp, but you're trying to learn from it? If not store it and get the $$ to fix it.

If you're playing with it and you're not trying to fix it... The ohm sensor can give you an idea what is shorted, most diode or transistor will short, but at some rare times they are opened.


BTW check those diodes or translator with the amp is dead, pull the AC cord out.