Princeton Reverb = Thin/Plucky?

[DMichel123]

I know, doesn't sound right to me either. I've got a SFPR on the bench right now. It sounds great at high volume/distorted, but the clean sound is, well, plucky. That's the best I can describe it. It doesn't have the warm, full tone I expect out of a vintage Fender at ALL. I've messed with modding the PI, got the voltages up, but it just breaks up sooner. I will be changing the cap can, bias cap, and e-lytics on the board this weekend. I suspect new tubes may be needed as well. In my experience though, amps needing tubes/caps generally sound about the same before replacement. They might get tighter afterwards, but this one seems REAL tight... The bottom end and low-mids are very wimpy...

Danny

 

[Jamar]

i'll preface this by I know nothing about fixing amps that said:

I just sold a blackface deluxe reverb that had the same symptoms. If I would bump the top of the cabinet with my fist in the right spot, the sound would kick back in. The fella I sold the amp to, said he had seen that with several older amps. He suggest a loose solder joint somewhere on the board. It didn't make him flinch when buying the amp. The amp still worked fine but sounded a little thin, and when you hit it, the volume would up a good bit then the bass and mids were all of sudden more pronounced.

I had the amp serviced by three different competent and qualified technicians over the last year. None of them caught it.

 

[phsyconoodler]

Quote: "I suspect new tubes may be needed as well. In my experience though, amps needing tubes/caps generally sound about the same before replacement."

Then why change the caps and tubes if they won't sound any different?
Sounds like the cap job and tubes should do it.That is unless the speaker is what's wimpy.

 

[fender753]

Maybe I'm the only one but I think the same thing about Vibro-champs, it might just be the smaller speaker or smaller cab, or there could be a problem with your amp.

 

[DMichel123]

What I meant was that the sound of the amp in general doesn't change drastically... Same basic tone... maybe a little louder/tighter... but still sounds like the same amp...

 

[phsyconoodler]

The speaker makes a HUGE difference.

 

[DMichel123]

The speaker in the amp is a Weber C12N (12F150 now?) I've tried it through other speakers... it sounds the same. I would expect this amp to have more bass, or looser bass... the little bass it has is tight sounding(I think that's why it sounds plucky) The high end sounds incredible...

 

[Billy Penn]

Maybe the slope resistor is open? Does the bass pot work? Or maybe one of the tone stack caps are bad (.047 or .1?).

 

[DMichel123]

The bass pot works(esp. 0-3ish) I'm gonna change all the e-lytics. In the meantime, any suggestions will be greatly appreciated.