Gibson GA-30rv
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Blacktweedplexiface
- Posts: 7
- Joined: Mon Sep 28, 2020 5:01 pm
Gibson GA-30rv
I have a chance to purchase a Gibson GA-30 amp, early 60s tweed. The reverb is not working and the 60 cycle hum is really loud. I am thinking about buying to fix up and sell or keep, not sure yet. Is $800 too high for a project like this? It has original speakers and transformers, and looks like someone made a sorry attempt at replacing filter caps, it other than that, all original. Not many for sale to compare, but there is one on reverb for $1700. Give me your thoughts.
Re: Gibson GA-30rv
There was a time when I was a fan of some of the more off beat Gibsons. I've got two of them, GA20-RVT and GA17-RVT. They've been in a closet for years. Maybe I will get them out again sometime.
I believe you have a GA30-RV Invader? Tweed cab, 12" and 8" speakers (weird.) 3-6EU7, 12AU7A, 2-6V6, 5Y3. Made in 1961. Info says they shipped 715 units.
In 1962, that model was built as part of the Crestline series and lost it's tweed. Tube compliment changed, obviously a different amp with the same designation:
4-6EU7, 12AU7, 2-7591, 5AR4 (most likely corresponding to Epiphone EA-12RVT Futura)
or 4-6EU7, 2-12AU7, 2-7591, 0A2
In any case, the schematic suggests this is an ordinary amp and not one of the ones that has what I'll call Gibson weirdness in the circuit, like the terrible notch filter in my GA20-RVT.
These were, IMHO, not terribly popular amps and there must have been a reason. We can speculate about that...
I suggest, as long as the reverb tank seems to be in working condition, you can fix the reverb. If the tank is the problem, you can probably find a reasonable replacement, but it will never equal the Gibbs or Hammond tanks they used back in the day.
You can probably fix the 60Hz hum with a cap job and a 3-prong plug, but there are no guarantees. Heater wiring is iffy on some of them. If you have 120Hz hum, you will need to hunt it down. You may have both types. It may be hard to hear the 120Hz when the 60Hz is loud.
I'd expect this amp needs some TLC and I'd prepare to spend some hours fixing. This will be a labor of love, not something a tech can make money on. So, $800? If the cab is nice, speakers are good, iron is working, maybe good tubes, I might be willing to spend $500. I don't have a rationale for saying $500, but that is my pricing sensibility on it. I'm sure others might feel different.
Some thoughts on the price. There is no real market for a reason, probably the same reason, in general, that Gibson wasn't known for its amps. $1,700 is for a collector's piece. This isn't one of those. You might fix it in an hour or two for $50 worth of caps, a 3-prong cord, and a leaky coupling cap or open resistor in the reverb circuit. You might spend quite a bit more and not resolve the problems. You should plan on an investment of time.
Good luck!
I believe you have a GA30-RV Invader? Tweed cab, 12" and 8" speakers (weird.) 3-6EU7, 12AU7A, 2-6V6, 5Y3. Made in 1961. Info says they shipped 715 units.
In 1962, that model was built as part of the Crestline series and lost it's tweed. Tube compliment changed, obviously a different amp with the same designation:
4-6EU7, 12AU7, 2-7591, 5AR4 (most likely corresponding to Epiphone EA-12RVT Futura)
or 4-6EU7, 2-12AU7, 2-7591, 0A2
In any case, the schematic suggests this is an ordinary amp and not one of the ones that has what I'll call Gibson weirdness in the circuit, like the terrible notch filter in my GA20-RVT.
These were, IMHO, not terribly popular amps and there must have been a reason. We can speculate about that...
I suggest, as long as the reverb tank seems to be in working condition, you can fix the reverb. If the tank is the problem, you can probably find a reasonable replacement, but it will never equal the Gibbs or Hammond tanks they used back in the day.
You can probably fix the 60Hz hum with a cap job and a 3-prong plug, but there are no guarantees. Heater wiring is iffy on some of them. If you have 120Hz hum, you will need to hunt it down. You may have both types. It may be hard to hear the 120Hz when the 60Hz is loud.
I'd expect this amp needs some TLC and I'd prepare to spend some hours fixing. This will be a labor of love, not something a tech can make money on. So, $800? If the cab is nice, speakers are good, iron is working, maybe good tubes, I might be willing to spend $500. I don't have a rationale for saying $500, but that is my pricing sensibility on it. I'm sure others might feel different.
Some thoughts on the price. There is no real market for a reason, probably the same reason, in general, that Gibson wasn't known for its amps. $1,700 is for a collector's piece. This isn't one of those. You might fix it in an hour or two for $50 worth of caps, a 3-prong cord, and a leaky coupling cap or open resistor in the reverb circuit. You might spend quite a bit more and not resolve the problems. You should plan on an investment of time.
Good luck!