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 (http://www.houstonamp.com/)
Fuller's Vintage Guitar (http://www.houston.com/fullers-vintage-guitar-b3689691)

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?