Tubes for PRRI

Discussion in 'Glowing Bottle Tube Amp Forum' started by blille, May 31, 2018.

  1. blille

    blille Tele-Afflicted

    Posts:
    1,193
    Joined:
    Sep 22, 2016
    Location:
    Bay Area - California, USA
    Hello wise people.

    I have a PRRI with a 1x12 (CRex) incoming.

    Since I also have a 5e3 I plan to use the PRRI mostly for the classic cleans. I will use it for Jazz and P&W. I plan to get a couple of tubes and wanted to get your feedback.

    V1 Preamp: likely a NOS RCA 12AY7 - loved it on my 5e3 and I would like to tame the amp a bit since like I said I plan to use it mostly for cleans up to breakup. Also read great things about 5751 in this position but I have no experience.

    V2 Reverb Driver: 12AU7 - I just need a bit of reverb. Any recommendations? Is NOS worth it for this position?

    Thoughts?
     
  2. strat a various

    strat a various Friend of Leo's

    Posts:
    3,273
    Joined:
    May 9, 2008
    Location:
    Texas
    It will be super quiet with a 12AY7. Set on 6 at the volume, it'll be like "2.5" with a normal 12AX7. If you are concerned with distortion, which sets in around 6 on the volume knob, (depending on the tone settings), just plug into the low dB input. Backing off the guitar volume will have the same effect.

    If you find the threshold of distortion with stock tubes ... it will never be louder than that with less distortion, not accounting for the speaker. Your settings will change, but your clean volume won't go up.
    C Rex is a loud speaker, but it breaks up a bit, too. Quieter V1 tube won't get more clean volume from that speaker, just more wiggle room on the knob.
     
    BelairPlayer likes this.
  3. blille

    blille Tele-Afflicted

    Posts:
    1,193
    Joined:
    Sep 22, 2016
    Location:
    Bay Area - California, USA
    Thanks. I’m going to get a new tube for v1 so I can choose 12ax7 or anything else. I was thinking 12ay7 because I don’t think I’ll use the distorted sound, IME they tend to be cheaper and I will appreciate having more granularity in the volume dial. Totally get that hitting with more or less volume gets a similar effect.

    Yes, I’m not delusional that a quieter v1 will give me more actual headroom. Part of the thinking was getting a very efficient 12” speaker to make up for the loss in volume.


    Any recommendations/thoughts for v1 and v2?
     
  4. strat a various

    strat a various Friend of Leo's

    Posts:
    3,273
    Joined:
    May 9, 2008
    Location:
    Texas
    NOS 12AX7, JAN 12AT7 or any non-microphonic 12AX7, and any 12AT7
     
    blille likes this.
  5. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    3,772
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    5751 is also a popular v1 tube.
     
  6. uriah1

    uriah1 Telefied Gold Supporter

    Posts:
    21,212
    Joined:
    Feb 12, 2011
    Location:
    Around
    5751 and some black plate 6V6
    That speaker may be a tad dark.
    imho
     
    BelairPlayer and LAGinz like this.
  7. blille

    blille Tele-Afflicted

    Posts:
    1,193
    Joined:
    Sep 22, 2016
    Location:
    Bay Area - California, USA
    Thanks! I’m going to go with a JAN GE 5751 mostly based on recommendations from here and the Jazz Forum.

    I’m not touching the power tubes yet to avoid biasing but that might be next
     
    Last edited: Jun 2, 2018
  8. Tone Chase

    Tone Chase Tele-Meister

    Posts:
    369
    Joined:
    Aug 20, 2014
    Location:
    Windsor ON Canada
    I have a Fudge Brownie PRRI version, and I wasted considerable time and money on tubes, speakers, etc.

    It is back to all stock, as delivered. I concluded that Fender just got this particular amp as right as could be. I play through this amp just about every day, and I have had well over twenty good amps at the same time to choose from.
     
    BelairPlayer and blille like this.
  9. LudwigvonBirk

    LudwigvonBirk Tele-Holic

    Age:
    118
    Posts:
    891
    Joined:
    Aug 26, 2017
    Location:
    Madison
    I have yet to find a tube for any slot in a PR that is a true game changer*. I have a stock silverface and build clones for fun. Have tried stokes, paulc, and other mods, and a bunch of 10 and 12" speakers. I play (jazz combo stuff) every week with one of them depending on the capricious moods of the trade winds and planets...

    Assuming you have a nice-enough-behaving tube in V1 (and ideally a good spare), please consider swapping in an Allen T020 Output Transformer. It is easy to install and costs around $80. It makes a big difference in the clean sound, you can hear it instantly and from what you said above I bet it will be a positive for you. Easily reversible if it isn't for you.

    *hook me up if you have a true game changer tube recipe that you yourself have tried. If it isn't insanely expensive I'll gladly try it.
     
  10. blille

    blille Tele-Afflicted

    Posts:
    1,193
    Joined:
    Sep 22, 2016
    Location:
    Bay Area - California, USA
    Tell me more about what the T020 did for you.

    I found this thread on the installation and it doesn't look too painful. https://www.thegearpage.net/board/index.php?threads/prri-allen-t020-install-pics-notes.665239/
     
  11. LudwigvonBirk

    LudwigvonBirk Tele-Holic

    Age:
    118
    Posts:
    891
    Joined:
    Aug 26, 2017
    Location:
    Madison
    Last edited: Jun 3, 2018
  12. darkwaters

    darkwaters Tele-Afflicted

    Posts:
    1,487
    Joined:
    Oct 14, 2012
    Location:
    Newfoundland
    Highly recommend a 12ay7 in V1. Personally, I'm never going back to a 12ax7. Tried a 5751, but, honestly, I couldn't hear any difference compared to a 12ax7.
     
  13. blille

    blille Tele-Afflicted

    Posts:
    1,193
    Joined:
    Sep 22, 2016
    Location:
    Bay Area - California, USA
    Awesome, thanks!



    Now you tell me?! Lol

    I was planning to put a 12AY7 but nobody vouched for it so I ended up ordering a highly recommended 5751. I'll give it a try with the 12ay7 I have on my 5e3
     
    Last edited: Jun 3, 2018
    zephyrR1 likes this.
  14. thebowl

    thebowl Tele-Meister

    Posts:
    331
    Joined:
    May 19, 2014
    Location:
    New Jersey
    I have an old Sylvania triple mica 5751 in V1 right now. As others have said, they are very quiet.
     
    blille likes this.
  15. AxemanVR

    AxemanVR Tele-Afflicted Ad Free Member

    Posts:
    1,773
    Joined:
    Dec 27, 2011
    Location:
    Minnesota USA
    `
    Just food for thought:

    I decided to try switching from a 12AX7 to a 5751 on my AA764 Fender Champ based amp and while I love how it sounds with my guitar turned all the way up, when I back off the guitar's volume the treble roll-off is noticeably more drastic with the 5751 than the 12AX7, so I went back to the 12AX7.

    I can only guess that the gain structure somehow changed the amp's voicing in some unwelcomed way, so you might want to keep that in mind as well...

    Good Luck!


    `
     
    Last edited: Jun 7, 2018
    blille likes this.
  16. jrblue

    jrblue Tele-Afflicted

    Posts:
    1,763
    Joined:
    Nov 14, 2010
    Location:
    Santa Barbara
    I like 12AU7s in both positions, though to be honest I never use amp reverb anymore. I like the low power preamp tubes and find that the overall amp volume is still plenty (though I almost never crank it anyway). There are excellent NOS AU7s out there, though the tube is becoming really popular for the reasons I mention. But jeez -- I've been able to find military spec versions of AU7s by great makers for very little, through patient searching. I love the response, the tonal results, the extremely low noise, the feel and headroom... Good luck! Personally, I like your thinking about how to tube this amp.
     
    blille likes this.
  17. strat1

    strat1 TDPRI Member

    Posts:
    32
    Joined:
    Jun 28, 2003
    The PRRI comes with stock EH tubes if I remember correctly. I replaced them eventually with Tung Sol RI's, but I saw no need to alter the tube config. Mine is clean up to five or so on the volume dial, and the reverb is great on 2.5 or so. It is not a loud amp, only 12 watts or so, so the headroom is there, and it sounds great. Why not give it a chance before you start investing in new tubes. Just a thought.
     
    blille likes this.
  18. MattyK-USA

    MattyK-USA Tele-Afflicted Silver Supporter

    Posts:
    1,846
    Joined:
    Feb 22, 2018
    Location:
    Savannah GA
    I can't bring myself to touch the stock tubes. 65 Tweed PRRI and it was just what the doctor ordered in my case. I've gone all Rick Astley on the damned thing.
     
    blille likes this.
  19. blille

    blille Tele-Afflicted

    Posts:
    1,193
    Joined:
    Sep 22, 2016
    Location:
    Bay Area - California, USA
    I got my GE JAN 5751 for v1 and RCA 12AU7 for v2 earlier this week.

    For v1 I was considering going lower to 12ay7 but yesterday I spent all day playing through it and I’m sold on the 5751. I plugged in 2 and can go clean almost all the way unless I dig in of course. The best way I can put it is that it sounds more “fendery”, chimey?

    v2 is a winner. Not only the amount of reverb is more manageable, it also sounds “better” I can’t point my finger at why. Maybe some more mids? Or just less treble?

    I also noticed that my cheap jazz partscaster with a neck SD 59 with A2 is sublime. However my ES-330 like Peerless (hollow, P90s) does not shine.

    I’m also really happy with the speaker.
     
  20. blille

    blille Tele-Afflicted

    Posts:
    1,193
    Joined:
    Sep 22, 2016
    Location:
    Bay Area - California, USA
    I’ve played with tubes and left stock in the past. To me part of getting to know an amp is hearing how slight tweaks sound like. They may stay or not.
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.