Gibson GA 30 RV

[jyant]

I recently acquired a Gibson GA 30 RV that came in a deal with a Gibson ES 335 guitar. The guitar is nice but I am not happy with the amp.
The amp came with two 12" C12Q Jensen speakers. I didn't like the tone ( too basey, not enough treble) so I took it to a tech who replaced the caps and some resistors. The tone still was too basey so I replaced one of the C12Q's with a C10Q I had. The tone is still too basey. I understand that the original amp had a 12" and an 8 " speaker. I could get an 8" speaker and try that but I think there is more of a problem here than just the speaker.
Would anyone have any suggestions as to what I might need to do?
Any help is appreciated!

[cbarrow7625]

Do all of the values in the amp circuit match the original schematic of the amp? That is a pretty critical piece of missing information. If the previous owner mess with the speakers they may have also messed with the schematic. It's pretty simple & basic.

Here is a link to it:

http://www.prowessamplifiers.com/sch...n/Ga_30rv.html

[jyant]

Thanks for your input. I'll have this checked out

[Tubenit]

more treble

You can change the cathode cap on V1 from a 20uf to a 5uf and change the coupling caps from .02 to .01 after the first gain stage. That should help with more treble and less bass.

I should mention that I have owned an amp with an original '62 Jensen C12Q and did not find the speaker to be too bassey at all. I am dubious the speaker is the problem?

With respect, Tubenit

[Enzo]

And don't overlook the possibility that you simply don't like the sound of this amp, rather than it having some problem.

[TD_Madden]

Enzo,

It's taken me a long time to recognise that not every amp's tone can be bent to my will.....

I'm finally getting to the point where I'm unloading those amps whose sound I don't dig...after too many speaker replacements and/or component tweaking.

[jyant]

Gibson GA 30 RV

Thanks everyone for the posts and suggestions. I think I will try
tubenits suggestions. I really don't think the speakers are the problem.
I listened to a GA 30RV at the Dallas Guitar show last year and it had a different tone than the one I have.

[capnjuan]

Hi Jyant; I have a GA30RV with original but reconed Jensen P12R and 8CS speakers; I also put a 4uf/250V non-polarized cap in the supply to the 8" speaker to keep it from breaking up too quickly. My has been reconditioned throughout and has a premium tube set in it. I don't find it too bassy but then everyone's tastes are different. Try the change to the cathode resistor bypass cap but if you don't think you can get it where you want it to go, pass it on and find something brighter,say, in an EL84 amp for example. Good luck witih yours. CJ