Found a 64' Gibson Skylark. Help

[Futureminiondad]

I just found this amp and it looks like its in good condition from the front of it. I had a feeling it might need some work, but for 50 bucks I thought it would be a fun little project to learn to repair. The electronics look pretty bare, nothing too complex, but I'm definitely unexperienced.

Anyways, when I turn it on I notice it's not making any noise if I remember, but I then notice the fuse in the amp was shattered, don't know how that happened, but I replace the fuse. Then I turn it on. It has a loud hum that lowers once you turn the up "loudness" knob. Seems like the tremolo is always on in spite of it being on or off, though I can't really tell because the signal coming out is soo distorted.  I know with old amps the caps can go bad and maybe the tubes in it are bad, so any insight would be greatly appreciated. If anyone knows where I can find the parts and a schematic, I would greatly appreciate that.

[badbluesplayer]

You probably have the Skylark "Crestline" model.  Check the tubes in it.  If it has one 6EU7, one 6C4, two 6AQ5's and one 6X4, then that identifies the circuit.  Is that the one you have?  If so, then here's the schematic -

http://www.0rigami.com/gg/ga5_crest.pdf

 

If you have one with a 12AX7, a 5Y3 and a 6V6, then it's another circuit.

You can probably get all the parts you need from Amplified Parts.  They have the replacement "firecracker" style capacitors that you'll need.  They also have the other smaller caps too - https://www.amplifiedparts.com/

 

I work on vintage Gibson amps, so ask any questions you want.  I usually replace the power cord and replace the electrolytic capacitors on all old Gibsons first.  Good luck!

Edited March 6, 2020 by badbluesplayer

[JETEXAS]

On 3/6/2020 at 7:16 AM, badbluesplayer said:

You probably have the Skylark "Crestline" model.  Check the tubes in it.  If it has one 6EU7, one 6C4, two 6AQ5's and one 6X4, then that identifies the circuit.  Is that the one you have?  If so, then here's the schematic -

http://www.0rigami.com/gg/ga5_crest.pdf

I just picked up a 64 GA-5T as well, and it has the 5 tubes, but there's 6EU7 tubes in both V1 and V2. Was that ever a configuration or do I need to track down a 6C4? 

https://photos.app.goo.gl/LwM6sXB39ZCLMLgN8

https://photos.app.goo.gl/6Q1eFi2KN5C94JQL9

My amps plays, but it's got a noticeable hum even with nothing plugged in. The tremolo also doesn't work. Sometimes I can hear it oscillating in the hum, but it doesn't actually affect the guitar.

I guess I'll start with the capacitors and go from there.