Help needed with GA-19 RVT

[ojaverde]

I just picked up a 1963 Falcoln GA-19 RVT on Ebay.It seems to be all original and Except for the chrome plating coming off the chasis it's in pretty good shape. It sounds good , but the tremolo doesn't work. I tried switching the 6EU7 tubes around in V1,V3 and V4 but it still won't come on. The reverb works great. Does anyone have some trouble shooting tips I can try or is it time for a trip to the amp tech? I have attatched the scematic. My amp has a 6C4 intead of the 7199 tube in V2. It looks like V4 is the tube that drives the tremolo. Do I have that correct?

[Cleeve]

V4 is the trem, the switch must be there and working in order for it to come on, looks like on the schematic that the foot switch just shorts the center of the connector to the chassis for the trem to be on. If the switch checks out, the next weak link is the capacitor connected to the cathode of V4.

[Teleasat]

Here's a few links about the GA-19RVT over at the Guild Forum. There's a guy over there that's really knowledgeable about he old Gibson amps. Hope this helps.

http://www.letstalkguild.com/phpBB2/...hp?f=9&t=12859

http://www.letstalkguild.com/phpBB2/...hp?f=9&t=12846

[ojaverde]

I got the tremolo working now. Turns out it was a deffective footswitch. Now, can anyone tell me how to slow down the tremolo? Lokking at the schematic there are 4 caps in the trem circuit. One is a 20mdf, and there are three 0.47uf caps. Which values do I need to change, and to what?

[Cleeve]

Try swapping the 47k resistor that goes to the wiper of the tremelo speed control to a higher value like 100k-250k..

[ojaverde]

I thought I had this fixed but no. I replaced the footswitch once and the first time I used the amp the trem worked fine. Turn off the amp, and the next time I turn it on the trem doesn't work again. I replace the footswitch and fire it up and it works again. Turn off the amp, go away, come back and no trem. So, at this point I have replaced the footswitch cable and the footswitch. I have checked the continuity on the cable and switch and they are both good. Iv'e replaced the two .047 caps and the 2.0 cap. Still no trem. What should I look at next? Or is it time to take it to a tech?

Can this amp be turned on without a speaker attatched? I have to unsolder the speaker wires to take the chasis out of the cab ( no 1/4 inch jacks here). Or should I just use some longer speaker wires ?

[TyPierce]

I unfortunately don't have any helpful tech info to offer, Ojaverde, but I just wanted to wish you luck on restoring your Falcon to full tonal condition - they are amazing amps with such cool vibe and tone, and well worth the effort. I played through one years ago and loved it, so congrats on a great amp!

[Citizen_Insane]

I would definitely not turn on the amp without the speaker plugged in, everything I've heard says make sure not to do that with a tube amp.