Princeton Reverb II

Discussion in 'Amps and Cabs' started by ScottB, Sep 27, 2005.

  1. ScottB

    ScottB Gold Supporting Member

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    I've got a Fender Princeton Reverb II. This is a Rivera designed amp from the early-mid '80's.

    I love the clean channel, no complaints there. Sparkly and punchy, probably the best clean sound I've got.

    My problem is the gain channel. I bought this amp largely on the strength of reviews in places like Harmony Central, etc. And these reviews were largely positive.

    Personally, I think the gain channel sounds kind of farty, especially with the gain cranked.

    Does anyone else have experience with this amp? Are there mods I can make? Are there components that may have failed or degraded? I've done quite a bit of tube swapping, and I think I've taken that as far as I can go. I also contructed a footswitch based on info posted on the PRII unofficial site:

    http://www.geocities.com/princerev2/

    Scott
     
  2. jpagey

    jpagey Member

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    I have a Super Champ. The lead channel always sounded weak until I put in a Emi Ramrod. I tried a Emi Ragin Cajun and that sounded great as well.) I suggest a Emi Texas Heat or a Governor speaker for your PRII. The key is keep the volume, treble and mid knobs at 5 or less, pull out the boost knobs and turn up the master volume and lead level knobs. I think these amps sound best when the power tubes are cooking.
     
  3. ScottB

    ScottB Gold Supporting Member

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    It definitely needs some power level to perform. There's a distinct change in the gain channel sound as the volume is turned up. Trouble is, my ears already ring all the time! I can't be in the same room with this thing when it is cranked.

    I was thinking about a HotPlate or maybe one of the Weber soak units.
     
  4. drbob1

    drbob1 Silver Supporting Member

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    A new speaker is a must. Mine came with the EV SRO which is pretty heavy and loud, but a perfect match for the amp.

    Also, it sounds WAYYYY better loud. In fact, as you may know, the gain structure is different depending if you're using the pedal or switching channels with the pull knob? IIRC, switching with the knob gives a lower gain, more saturated kind of tone that reminds me a lot of the drive on my Fuchs Mod-one of the best amps ever at bringing out those octave harmonics on held notes. An attenuator might help with that. BTW, yours is still running 6V6s right? I've heard of modding for 6L6s which seems like a bad idea for this amp...
     
  5. jpagey

    jpagey Member

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    I tried 6L6's in mine (before I put in the nice Emi speaker). The 6V6's sound much better to my ears.
     
  6. ScottB

    ScottB Gold Supporting Member

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    It is an idiosyncratic little mf'er isn't it? That stuff with the gain structure and the knob vs footswitch is downright funky.
    Mine actually came with 6L6's which I swapped out and rebiased for 6V6's. I've had a few different types in there, right now it's got some old grey plate GE's of a questionable vintage that I got in a good deal on ebay. It seemed to be doing fine on the 6L6's though. For all I can tell it must have been set up that way for quite a while. Didn't seem to cause any damage.

    Sounds like the attenuator is the way to go. Maybe a new speaker too. Mine actually came with a ripped Fender special design (original?) installed. Cowtown Guitars (Las Vegas, NV) sent me a Kendrick that they had lying around. Good shop. Good support.

    Anybody else got any speaker suggestions?
     
  7. riverastoasters

    riverastoasters Member

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    I wouldn't mod the amp - in the end if you don't like it, there's lots of other stuff to use and there aren't any more Princeton Reverb IIs being made.

    I agree with the alternative speaker advice. If you can, play it through a bunch of different speakers to see what it wants.

    Have you tried an attenuator? That can help effectively stiffen the speaker and still let you crank the amp.
     
  8. stratopastor

    stratopastor Member

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    hi guys

    there's a thread on the F*nd*er F*r*m right now in which another PRII-using friend finds the lead sound comes 'right' for him if he whacks the reverb up to 8!

    I'm considering an attenuator because I love the sound of the output stage working hard but the lead sound (preamp distortion) just doesn't do it for me. However, next time I'm playing around inside the amp I will try increasing the value of the coupling cap in the 'lead' path, which apparently makes it less buzzy and more growly.

    Amen to the speaker advice. I use a reissue Jensen C12N.

    The 'different gain structure with the footswitch' myth carries on... but no-one will justify it from the schematic! The clean sound DOES change with the f/s, but that's not the reason.

    As stated on the PRII page, I'm still collecting PRII serial numbers to verify how many were made... tell me yours and I'll give you a date for your amp...

    best wishes!

    SP
     
  9. Sudsysul

    Sudsysul Member

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    This is a great little carry-and-go amp. I used mine last night at practice with a Real Tube pedal for drive. I love this amp and will never get rid of it (famous last words around here, probably the kiss of death). I swapped lots of speakers and settled on a Celestion G12H.

    My advice is to skip the drive, find a nice pedal that floats your boat, and leave the amp unaltered. It's getting older every day, it's point to point wired that sounds great.. could be a keeper some day.
     
  10. drbob1

    drbob1 Silver Supporting Member

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    Interesting comment SP. Having read quite a bit on this, I've heard some explanations that seemed to make sense. That said, channel switching does sound different to my ears depending if I'm using the knob or the FS. Do you disagree?
     
  11. narapo

    narapo Member

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    PR II & attenuator : I have an horror story to tell !

    I have got a Princeton Reverb II on the fleabay a few weeks ago. I seemed to be in good overall shape. I liked the clean sound a lot, but was a bit dissapointed with the lead "channel".

    I wanted to crank the amp with an attenuator (Komet airbrake) ; only a few minutes after hard play, sound went down and smoke up ; I just had a few seconds to switch it off . I believed my amp has just died, but found that only one of the 6V6 was. I have replaced both valves with a couple of identical spares ; no rebias was made, I replaced 2 Mazda 6V6 by exactly the same tubes.

    The amp went up again, nice clean sound, but after some 5 minutes of play, again the sound is going down, and I smell a burning valve, so switch off again, and same 6V6 has died.

    The amp will go to a tech for complete checkup. But I don(t know what went wrong. Were the tubes bad / too old ? Problem with the attenuator ? it was OK with other amps...

    Maybe I should have rebias after puitting the same valves ? must I ask the tech to put some bias pot ?

    Any comments wellcome
     
  12. ScottB

    ScottB Gold Supporting Member

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    SP,

    I had sent you all of the numbers I could find a few months ago, when I was initially focused on this amp.

    I've gotten a lot of GAS out of my system lately, and now the PRII is grabbing my attention again!
     
  13. ScottB

    ScottB Gold Supporting Member

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    Be afraid, be very afraid!

    So has anyone else run this amp with an attentuator? Could the problem described by narapo be attributed to age and running at high ouput power?

    Narapo, if you haven't already, I would (or have your tech) install the screen grid resistors as desribed on SP's website:

    http://www.geocities.com/princerev2/modifications.html#reliability

    I think it saved mine when I (somehow-doh!) managed to plug my tubes in with the pins in the wrong position. A little smoke and - poof! It may prevent whatever is blowing your tubes from causing additional damage.
     
  14. CitizenCain

    CitizenCain Member

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    Yup, definately do the reliability mods on Stratopastor's PRII site, especially correcting the undersized (power wise) bias feed resistor. I had a PRII go up like that when I was pushing it hard. Not through an attenuator, just blasting it, but I would always make those mods to these amps.

    For a speaker, check out a Weber ceramic Sig 12. I used one in a Deluxe Reverb II and it was great! Marriage between the C12N and Brit sounds, it's got a Brit cone. It worked real well in my DRII.
     
  15. narapo

    narapo Member

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    This is the one I got in my PR II, and I liked the sound (when I got sound :( )
     
  16. stratopastor

    stratopastor Member

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    Narapo - shame about the Mazda.

    I agree with Scott, so I think the whole story is; if you want to run the PRII on"10" ...
    (a) add screen grid resistors
    (b) check the bias on the 6V6s
    (c) run it hard without attenuator
    (d) add the attenuator

    can I have your amp's serial number?

    -------------

    Bob - channel switching...

    (a) everyone's PRII behaves a little differently in this department
    (b) on most PRIIs the CLEAN sound changes significantly when you compare f/s with no f/s
    (c) on any PRII, the lead sound changes a little when you compare f/s with no f/s
    (d) (theory) BUT we think the lead sound changes a lot because we're A-B'ing it with a moving baseline, ie, the clean sound as in (b)

    I think I know why the sounds change; if you really want to go any further (abandon hope all you who enter here) see my

    www.geocities.com/princerev2/thescience.html

    and 'does it change the sound of the amp?' on

    www.geocities.com/princerev2/footswitch.html

    ----------------

    anyone else - can I have your PRII serial number? Post it here,PMme, or email me on stratopastor (at) hotmail (dot) com

    all the best

    SP
     
  17. ScottB

    ScottB Gold Supporting Member

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    I'll try to remeber to send it later tonight.
     
  18. ScottB

    ScottB Gold Supporting Member

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    Oh, I just realized you were probably addressing narapo. :D
     
  19. narapo

    narapo Member

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    Thanks for the advice, and sure, I will get that serial # for you tomorrow
     
  20. fareastchicago

    fareastchicago Member

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    hey there prII folks,
    another satisfied owner here....currently have a JBLd120f in mine and it's killer sounding and hard to beat...

    however, still wonderin' about a couple of things...

    1) anybody put in a "vintage" p12n (50watts) in their prII ????
    - very partial to alnico's....so, just wonderin' how it would sound

    2) thinkin' real hard !!!! about using a 15inch speaker in a custom-made combo cab for this little prII monster....
    - any pros/cons about doing this.....been reading up about these amps and nobody seems to try this baby with a 15inch speaker

    appreciate any replies.

    stratopastor - ob-1 of prII's...pls. advise
     

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