Gibson Amp GA 19 RVT (19 watts) I need help to choose te best tubes
Posted 14 November 2012 - 04:56 AM
i need a help, more specifically a technical opinion.
I have a Gibson Amp: model. Falcon GA 19 RVT (19 Watts with a 12" Jensen Speaker)and i need to replace the tubes.
- First question: how many tubes have this amp?
- Second question: what are the best tubes (reference, model, brand, ...) recommended to keep the original sound?
- Final question: is easy to make this replace? Plug and play?
Posted 14 November 2012 - 08:47 AM
maybe drop this in the Gibson Amplifier pages.
but in the mean while,,
here's a schematic
Looks like a combo of tubes from that schematic, they are all listed there.
for ordering, I'd go here:
I like Mullards, Electro Harmonix get good reviews, and lots of folks like JJ tubes.
I'm not sure about plug and play, if it's a class A amp, probably..
You can send Gibson Customer Service an email someone may be able to help.
and I found this just by doing a few googles
"1963 Crestline series Falcon with Loudness, Tone, Reverberation, Speed & Intensity controls. Attached footswitch for trem & reverb. 12-inch CTS ceramic speaker. 6EU7, 7199, 6V6 & 5Y3 tubes I believe"
Posted 14 November 2012 - 09:29 AM
I don't know the amp, so this may be all for not. But regarding amps with 6V6's, it is one of the LAST tubes you want to run at the wrong levels, as in most guitar amps, they are being used beyond their rated capacity in the first place. Also, new manufacture 6V6's are much different than NOS, so there really is no telling what the amp would be adjusted to as it is.
You can 90% of the time observe the plates and judge if they are glowing, but it's not 100% reliable, and it takes some practice. And NOS 6V6's you can't often see the plates.
Regardless, having the amp serviced should not be all that expensive, and it's WELL worth it to have the caps working good, and the power tubes biased.
Pre-amp tubes, feel free to swap away all day long. The only thing to worry about there is what they SOUND like to you.
Posted 16 November 2012 - 07:05 AM
Or maybe you have a '64/'65 model. These amps have a 7199 tube:
So once you figure out which one you have, then you can determine whether you need a 6c4 tube or a 7199 tube.
Other than that, you'll need three 6eu7's. Then the preaamp tubes will be set. There are not many brands of these tubes available, so buy whatever you can get that is made by any reputable manufacturer. Save the old tubes.
The amp does not have an adjustable bias, so you don't have to worry about that. You can plug and play as far as the power tubes go. JJ brand 6V6's are really tough, so they'd be a good choice to put in there. The tubes that are in there now may be fine and they may be valuable, depending on what's in there. Once the amp sounds good, you can stick the old 6v6's back in there to check if they're o.k and if they sound good.
I wouldn't worry about replacing the rectifier tube at this point unless you somehow determine that it's bad.
Kidblast posted the schematic for the '64/'65 model. Here's the schematic for the earlier models:
The other thing you can do, like Stein said, is to have somebody service it. You might need new capacitors, which can go bad in an amp that's as old as yours. But if you like to tinker with stuff, you can replace the tubes yourself, and then if it sounds good, you can just play it and see how it goes. If there's a bad cap, you'll probably hear something. You can always get it serviced in the future.