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I have a chance to work on and repair if possible, two what I believe to be 1966-67 era white panel 3 knob (vol, treble, bass) non trem GA-5 amps.

Local shop has these and while I was looking at them the store manager comes over and asks if I know anything about them as they both "sound bad". In the short time I had he turned them both on and one hummed loudly. Didn't have a chance to play through them yet.

Anyone know where I can get the correct schematic and, if possible, a layout? I can find the one for the volume only version but not the three knob.

Besides the probable need to replace the electrolytics, anything I should be looking for besides the obvious loose connections, burned parts etc.? I know that these are pretty basic so if I'm able to de-bug anything, it should be these.

If I take this on it sounds like they are looking for someone to work on old amps the get in so it sounds like a good learning experience if I can do it.

Thanks for the assistance.

Could be the GA-5t Skylark w/trem. Here are some schamatics.

GA-5 Skylark.
GA-5 Crest
GA-5t Skylark w/trem
GA-5 Les Paul Jr.

These are on http://www.schematicheaven.com/gibson.htm

Start by: Replace all the electrolytics, check for cold solder joints, investigate other caps.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Thanks Stephen, these are appearantly limited production 2 years only 1965 / 66. The GA-5T is closest, but these don't have tremolo, they're 3 knob (vol, treb, bass) only.

I guess that I could use the values and schematic for the GA-5T and drop off the trem circiuit from pin 3 of V1 and drop it to ground through the 202K resistor like the single knob GA-5 schematic. Or, I could just open them up and take a look : ) !

Do you have any good suggestions for cap supplies around here?

Thanks for the help.

Jack

http://www.justradios.com/ - Caps

http://www.hoffmanamps.com/ - lots of parts, N. C. tho

http://www.alliedelec.com/ - parts

There are lots more, but not sure how close they are to you.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps