Any good Ampeg techs in Cleveland?

deluxeg · #1 08-25-2011, 10:13 PM

I bought an Ampeg SVT-3 Pro on Ebay, it seems to be a 2006 model made in USA in good condition. I also bought a brand new Ampeg 610HLF but when I hooked up the amp through the speakon connectors using a brand new cable I got no sound, I switched to a regular speaker cable and got sound but it was very distorted at all volume levels and settings. I read about the bias adjustment for these amps but I wouldn't feel comfortable doing this myself. I called the Ebay guy and he said it was fine when he shipped it and that I should take it somewhere to get it looked at and he would pay for any repairs. Does anybody know a good place to take this amp to in Cleveland that would be familiar with them?

Jeff Scott · #2 08-26-2011, 08:06 PM

Can you get schematics for it?

**B-string** · #3 08-26-2011, 08:45 PM

Quote:

Originally Posted by Jeff Scott

Can you get schematics for it?

You probably could from Jerrold Tiers

Jeff Scott · #4 08-26-2011, 08:50 PM

If so, I know someone who could repair the amp.

Venom of God · #5 08-26-2011, 08:51 PM

Quote:

Originally Posted by deluxeg

in good condition.

I don't know if this part was true.

deluxeg · #6 08-26-2011, 09:42 PM

Thanks for the replies, by "in good condition" I meant visually. It has no scratches or dents on the outside and inside I didn't see anything physically broken. I also did some more investigation and I bought a different speakon cable and I got sound so apparently the first brand new speakon cable I bought was bad. That was what you get for spending 6 bucks on a 25' cable on amazon. The new 10' one from GC for 25 bucks works fine. I also tried to plug my POD into the power amp in on the SVT3 to bypass the preamp and I still got a distorted sound so it seems to be a classic case of the bias being off. I talked to a guy from a company called Beamish Electronics today. Anybody have experience with that company?

Jeff, who is the person you know who could fix it? I don't have schematics but I do know where the trim pot is on the circuit board that adjusts the bias. I just don't know how to make sure that it is adjusted to spec. All that I have is a multimeter from wal-mart, I don't think that is going to cut it.

Jeff Scott · #7 08-26-2011, 10:45 PM

My friend has been doing electronic service since we were in junior high school, I currently have a 1962 Fender Concert Amp with him to take care of the usual old tube amp stuff. By day, he designs and builds medical electronics and used to do space flight hardware.

Does the amp distort badly at all volume levels? It may be more than a bias issue, possibly blown output transistors. Have you tried running the preamp out to a different power amp to see how well the preamp section is working?

Mississippi Al · #8 08-27-2011, 12:30 PM

Quote:

Originally Posted by deluxeg

I bought an Ampeg SVT-3 Pro on Ebay, it seems to be a 2006 model made in USA in good condition. I also bought a brand new Ampeg 610HLF but when I hooked up the amp through the speakon connectors using a brand new cable I got no sound, I switched to a regular speaker cable and got sound but it was very distorted at all volume levels and settings. I read about the bias adjustment for these amps but I wouldn't feel comfortable doing this myself. I called the Ebay guy and he said it was fine when he shipped it and that I should take it somewhere to get it looked at and he would pay for any repairs. Does anybody know a good place to take this amp to in Cleveland that would be familiar with them?

Talk to Clyde at Timeless Guitars in Parma. He's a Bassist and knows his stuff

deluxeg · #9 08-27-2011, 12:31 PM

Just tried the preamp out of the SVT3 into the Micro-VR I bought last night hooked to the 6x10 and it sounds fine. So something seems to be wrong with the power section. But now that I have this micro-vr I won't feel so bad about sending the SVT3 out for repair for 7-10 days. Just hope it is simple as adjusting the bias and not anything blown up.

On a side note they had a display model of the SVT3 at Guitar Center on clearance for $679 and the salesman said that guitar center is not going to carry them anymore in stores. He also said that I was one of the only people to ask about and try the Micro-VR. I don't know if he was just yanking my chain so I would buy the display model or what.

runmikeyrun · #10 08-27-2011, 01:27 PM

I've worked with Beamish... they take f o r e v e r. I don't have any experience with Timeless. I used to take my vintage V-4 to a guy named Bill Kahle but that that was 10+ years ago. Don't know if he's still working on stuff or not. If you're interested in his email let me know i'll PM it to you.

Joe Smithberger · #11 08-27-2011, 07:57 PM

If you are up for a little drive, there is a very good guy in Canton. He works under the name of the Guitar and Amp Doctor. He recently rebuilt some amps for the Hot Tuna guys (Jack and Jorma). PM me if you are interested in more info.

deluxeg · #12 08-28-2011, 05:47 PM

Well I got bored today and decided that I would take a crack at fixing the amp myself. I got out my trusty walmart multimeter and screwdriver set and took some measurements. The readings on all the resistors were just about at 0. I then adjusted the bias pot a little bit and ended up with these readings.

The distortion is now completely gone. Thanks for the replies everybody.

**B-string** · #13 08-28-2011, 06:08 PM

PM Jerrold Tiers for the schematic, should have bias adjustment on the schematic. If you set the bias too hot you may just cause some very expensive damage! Don't run the amp again until you know for sure!!!!!

**B-string** · #14 08-28-2011, 06:10 PM

Zero may have been too cold (cutoff distortion) but too hot is very dangerous. Were those voltage readings in volts (V) or millivolts (Mv)?

deluxeg · #15 08-28-2011, 06:22 PM

Those readings are in mV. I based my adjustments on info I found in older threads.

**B-string** · #16 08-28-2011, 06:35 PM

Quote:

Originally Posted by deluxeg

Those readings are in mV. I based my adjustments on info I found in older threads.

You had me REAL concerned as mv was not stated in your post! JT is real good man and very generous with his resources and knowledge. Just to be sure you are in a safe range with that amp?

mam1862 · #17 08-28-2011, 06:44 PM

Try Empirical Sound in Cleveland.

runmikeyrun · #18 08-28-2011, 06:47 PM

Quote:

Originally Posted by Joe Smithberger

If you are up for a little drive, there is a very good guy in Canton. He works under the name of the Guitar and Amp Doctor. He recently rebuilt some amps for the Hot Tuna guys (Jack and Jorma). PM me if you are interested in more info.

I forgot about this guy. He's very friendly and knows his stuff.