1966 Princeton Reverb - Considering Buying One - Questions....

Discussion in 'Amps and Cabs' started by Krackle, Apr 22, 2015.

  1. Krackle

    Krackle Member

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    HI all,

    I read this forum all the time and finally joined to ask some questions about a 1966 Princeton Reverb I'm going to look at in the next few.

    It's pretty much all original..It has all the original Caps-Transformers, Speaker etc..I believe the speaker is original.

    Questions:

    I'm probably gonna get the amp recapped properly..this should tighten it up quite a bit, correct? I knooow this amp isn't gonna be playing up to spec..any recommendations on approach to this as far as quality parts go?

    Are their any typical issues on these Blackface Princetons amps that I should look for?

    When turned up to distortion levels is it typical for this amp to be a bit flabby sounding - especially in the lower sonic range? (I played a 70's Silverface a while back and found to be a little bit spongy in the lows)

    If this is typical..can anything (simple mods) be done to get a more crisp attack in the lows when pushing the amp..


    I want to play and record with this amp but I'm wondering about differences in value between "pre CBS" and "post CBS" Blackface amps? Obviously the 1966 I'm looking at is a post CBS version.

    Anything and all advice you guys have to offer - appreciated..
     
  2. swiveltung

    swiveltung Member

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    The PR will be flabby when played fairly loud. A loud efficient speaker helps. I doubt the filter cap can change will help. But played in the volume zone they are good at (very small club, recoding) they can really sing.
    What you are hearing just testing one is likely the speaker.
    no appreciable diff pre/post CBS.
     
  3. zenas

    zenas Member

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    Blackfaces the only change I've seen are the electrolytic caps inside. The earlier ones had the toilet paper roll looking ones and the latter BFs had plastic ones.
    Does that matter? Only if you're stupid enough to run 50 year old electrolytics.

    Cap can on a Princeton is a spot where stupid people screw up. Things look good and the amp don't hum they leave them. Then change half the amp to tighten the bass.

    Of course it doesn't help that even a healthy Princeton is going to be somewhat loose in that regard but leaving weak electrolytics in the power supply makes it alot worse.
     
  4. Jon C

    Jon C Silver Supporting Member

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    Agree with all of that. They're not at their best overly cranked, the sweet spot is down a bit IMO (dep. on the indiv. amp, volume ~5-6 or less?).
     
  5. Krackle

    Krackle Member

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    THnx Swivel,

    So, a complete recap won't help firm up the low end when pushing the amp?

    Does anyone actually leave the old blue caps in these amps?

    Here's a picture of the guts..

    [​IMG][/IMG]
     
  6. zenas

    zenas Member

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    Yes leave the blue caps in ! Or sell them! They almost never go bad I've never had a bad one.

    Do something stupid like a Dan Torres full amp rebuild (all new pots, resisters, caps) and your 2000 dallor amp is an 800 dallor amp.

    Electrolytics do go bad those are the paper roll ones and the cap can. Those go bad with time 50 years is about time on those.
     
  7. rockinrobby

    rockinrobby Senior member Professional musician ... Gold Supporting Member

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    Looks like a Craigslist $2200 PR to me… :eeks
     
  8. scmavl

    scmavl Enjoyer Silver Supporting Member

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    I'd make sure the reverb tank is original and not a newer Belkin or the like... and if it's not, that's a negotiation point.
     
  9. drpicklo

    drpicklo Supporting Member

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    If you decide not to go vintage the Morgan pr12 Is amazing...same tones but bigger tighter sound
     
  10. broken_sound

    broken_sound Silver Supporting Member

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    There's a '65 Princeton NR on Reverb right now with a 12" speaker installed. Just a heads up.
     
  11. zenas

    zenas Member

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    That is by the way what you want to see inside a BF Fender when you buy it. Well that or with the new electrolytics already installed by someone who did it right.
     
  12. Krackle

    Krackle Member

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    Hard to believe those caps don't go bad?? (What's so special about the blue caps? what's in em, doublemint??

    Robby...who are you? a Specter of some sort?? Well if you are , don't start levitating my furniture..my sofa won't survive the drop back to earth.

    Dr. Picklo..I went to Morgan's website..wish they'd post a comprehensive look at that amp..couldn't find anything..
     
  13. swiveltung

    swiveltung Member

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    YES... leave the blue caps in! (or send them to me for free replacements!)
    I just put old blue Mallorys back in a 65 DR for a buddy(someone had put in Orange Drops everywhere) Of course I tuned the amp up also , so hard to say, but he was astonished at the amp when he got it back!
     
  14. swiveltung

    swiveltung Member

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    Firming up the low end:
    A good speaker, 10F150T etc
    DR output transformer
    Adjustable bias
    Slightly bigger Filter caps. I've used 33/33/33/20 before. You can experiment with this by simply soldering in caps (maybe 10uf) on the posts of the existing cap can (in parallel)

    But that amp is super clean, I'd hate to see you mess with it. It sounds like maybe you should get a DR.
     
  15. jaded_musician

    jaded_musician Supporting Member

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    I have a 70's silverface converted to blackface with the DR output transformer and 12 inch speaker. It might be sacrilege to do that to a real blackface but little Princeton sings at high volume.
     
  16. Krackle

    Krackle Member

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    DR transformer? Im guessing "Deluxe Reverb" trannie.

    Sounds like that is an easily reversible modification. Dave Allen and Bill M's TO20 sounds about right for this?
     
  17. jaded_musician

    jaded_musician Supporting Member

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    The TO20 is exactly what I used.
     
  18. bigtone23

    bigtone23 Member

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    Don't overlook the bass knob setting. As the volume goes up, reduce the bass to keep from amplifying flabby low end distortion downstream. Usually a setting around 3 or less is all the bass knob can do relatively tightly.
     
  19. zenas

    zenas Member

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    Until the electrolytics are addressed talking about the bass response in a vintage Princeton Reverb is a waste of time.
    Like I said they have a weak power supply to start with, weak filter capacitors inside an old capcan make it weaker.
    Leaving that old can in because some idiot says it checks ok or looks good is an exercise in futility.
     
  20. Totally Bored

    Totally Bored Member

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    Remove the stock baffle and make or buy a baffle and plop a 12" in a PR. It will sound uber awesome :dude


    Here's the back of my 68 PR. I gig this amp all the time at open mics or when I sub in with another band. Plenty loud and I never get it past 4.

    [​IMG]
     

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