Old Gibson Amp

[jmartinbz]

I have a Gibson electric guitar amplifier that is old and is having problems. If I could get a couple of things it would be great.

1. A schematic for the amplifier. The only information I can give you is that on the from the amplifier it reads "Gibson Electric Guitar Amplifier SKYLARK" with skylark being in bold letters. There are 2 jack connections with a volume knob, tone knob, and Off-On-Polarity switch. The speaker in the back has a tag on the back that reads SKYLARK with the number 4276 it and the cable connections to it are green and black. I have checked with Gibson and they do not have a schematic for it.

2. Does anyone have a troubleshooting guide for typical things to look for on this amplifier?

3. If I am unable to identify the problem and fix it do you know where I could send the amplifier to get it fixed in the Houston, TX area?

Justin

[rf7]

1. Look here for the schematic: http://www.harpamps.com/gibson/index.html

2. Look at this: http://www.geofex.com/ and go to the tube amp debug section.

[Paleo Pete]

I usually ask around and find out where other local musicians take their amps for repairs. Unfortunately nobody around here has a great reputation, but I did meet a local guy not long ago who is very knowledgable so there's hope...he's an amp builder and I've played a few of his builds, really good soounding amps.

In Houston, I had my Peavey MX repaired at a shop on 59 north just before it crosses 610, can't remember the name of the shop but the guy is no longer with us I think, his health was not good and I heard he had passed away not long before I left town. There was a vintage guitar store, so far I can't find it by Google, but did find

Houston Amp Repair
Fuller's Vintage Guitar

And if you inquire at music stores they might have contacts or repair departments, but the best way by far is find out from local musicians.

By the way that's a great sounding practice amp, a local shop had one a while back and I got to play it a couple of times, almost as good as my Fender Champ, but cleaner. Still a very nice sounding practice amp. Gibson tended to build them more like hi-fi than the typical guitar amp, usually cleaner than Fender or Marshall, but very good sounding amps.

First thing I always look at is tubes...then bad solder joints, then capacitors.

[stokes]

http://schematicheaven.com/gibsonamps/ga5.pdf heres the schem for that amp.It is basically a Tweed Champ,just tweak the plate and cathode resistors on the preamp and the feedback and you will have a Tweed Champ.Whats the problem with it?