PDA

View Full Version : Princeton Reverb Experts?


FloridaSam
05-05-2008, 11:30 AM
I just picked up a 1979 Princeton Reverb (Pull boost is foot switchable).

1. Should the voulme taper on this thing? Mine went from off to loud pretty quick and starts breaking up around 3-4. I took out the crappy pre-amp tubes and there was an unlabled tube in the 12AT7 spot. I replaced that with a Mullard 12AT7 and replaced the 12ax7 and 7025 with Mullards as well. The amp sounds A LOT better with NOS tubes but still breaks up pretty early. The power tubes are new JJs.

2. Would swapping a 12AU7 in spot one, or other lesser gain tube tame it a bit or is there something wrong. The amp sounds pretty good to me and the reverb and tremolo both sound strong and good (as strong as a trem on a PR can be).

teleman1
05-05-2008, 11:50 AM
You want less breakup??? Check and see if it is biased properly. Also, I believe you can get hotter or colder JJ tubes that could make a difference. BUt try putting in a 12at7 in the 12ax7 slot,(number 1). If that doesn't do it for you try a 12au7. Don't let any chumps tell you your amp, with the push/pull is any lesser an amp than an early 70's. I have a push/pull and have been hard pressed to hear anythng better than mine.

slider313
05-05-2008, 11:59 AM
The JJ power tubes do add more volume. They seem to be more of a 7591A than a true 6V6 in tone. Try the new Tung Sol 6V6. They sound more like a good old 6V6 and hold up quite well.

FloridaSam
05-05-2008, 12:09 PM
Thanks guys. I used to own an old '74 PR about 15 years ago but my memory is cloudy :) I've read good things about the JJs and they seem to react more like 6L6 than my 6V6 amps. I have a ton of old RCA pulls so I think I'll try some lower gain preamps.

strat71
05-05-2008, 08:05 PM
Hi,
:agree i rebuilt a 78 PR last year, and i also had problems since it started to overdrive at 3 on the volume pot...

i checked everything three times before i noticed that the volume pot was linear...

change it with a log pot and you'll overdrive at 7/8 on the volume pot... as all Fender should be... :rotflmao

look at this (sorry in French)
http://tahitigtr.canalblog.com/archives/fender_princeton_reverb_1978/index.html

hope it'll help...
Ben