Question about Tubes for a CJ (Conrad-Johnson) Pre-Amp

Discussion in 'Audio Hardware' started by ATSMUSIC, Jul 17, 2009.

  1. ATSMUSIC

    ATSMUSIC Forum Resident Thread Starter

    Location:
    MD, USA
    I was recommended these tubes http://www.upscaleaudio.com/Russian-6H236922-Type-3_p_49.html so I am wondering if anyone has any experience with these?

    Also wondering what 6922 tubes people recommend for the most transparent sound?

    I am new with tubes so I really do not understand a lot about them.

    Thanks for any help.

    I have a CJ CT-6 in case that helps.

    Thank you! :righton:
     
  2. TommyTunes

    TommyTunes Forum Resident

    I would check with Andy at Vintage Tube Services http://www.vintagetubeservices.com/ and see what he has available. When I had my Permier 14, he set me up with some great tubes. I planning on ordering NOS for my CT-5 from him
     
  3. Mike in OR

    Mike in OR Through Middle-earth...onto Heart of The Sunrise

    Location:
    Portland, Oregon
    Well I can tell you that I have been buying gear and tubes from Kevin for more than 20 years. In addition to Andy, Kevin is a tube wizard. If he has a recommendation for you regarding tube type, you can bank on it. That said, if you have the cash flow I would consider experimenting with some NOS in the 6922 family. My personal faves have been the Mullard and Miniwatt E188CC and the Siemens CCa tubes. The nice thing about using NOS tubes is that on average, they will handle so many more hours of use before going noisy than that of current production. At least that has been my experience.
     
  4. dividebytube

    dividebytube Forum Resident

    Location:
    Grand Rapids, MI
    I've done some fairly recent 6922 tube rolling - though it was for a Bottlehead Seduction phono stage - and found the 6H23P to be a fine tube. Of course the rumor is that the 70s/80s production is better than the recent stuff. For NOS tubes, the Amperex / Made in Holland stuff is still decently priced and was a step up over the 6H23P. More general 'tubiness', warmth, 3-d kind of sound.

    I met Andy a number of years ago and yes, I can recommend him if you simply want the best tube for the application and don't want to fish around rolling tubes.
     
  5. macster

    macster Forum Resident

    Location:
    San Diego, Ca. USA
    Let Kevin know exactly what you would like to do, and follow his advice. I've done business with Kevin for at least 10 or so years and he has never ever provided less than stellar service. Also, he responds to your emails. He is the best (IMHO) at what he does.

    M~
     
  6. ATSMUSIC

    ATSMUSIC Forum Resident Thread Starter

    Location:
    MD, USA
    Man I would love to have the CT-5. :love:
     
  7. ATSMUSIC

    ATSMUSIC Forum Resident Thread Starter

    Location:
    MD, USA
    Yeah I emailed Kevin 3 or 4 times and he wrote back quickly and honestly. I asked him if buying the same tubes that are in my cj now from him would sound better. He told me CJ is good at screening tubes so probably not. It is nice someone is so honest when they are selling something.

    He then explained more about the tubes he recommended me in comparison to the type 2's that came with my preamp.

    I REALLY wish I had more of a budget or tubes but I dug myself a pretty big hole buying CDs the last couple years and now I am digging myself out of it. :shake:
     
  8. ATSMUSIC

    ATSMUSIC Forum Resident Thread Starter

    Location:
    MD, USA
    Yeah I think I will try the tubes he recommended. I asked him for the most transparent/Neutral tube. He also recommended some others with the caveat that they are expensive. He did not push the more expensive tubes in any way though. Really nice guy like you all said.
     
  9. Steve Hoffman

    Steve Hoffman Your Host Your Host

    I was told by many people that C-J's are hard on tubes. If so, this is a good reason to buy cheaper new and not N.O.S.
     
    sushimaster likes this.
  10. ATSMUSIC

    ATSMUSIC Forum Resident Thread Starter

    Location:
    MD, USA
    Thank you, Steve:righton:
     
  11. JA Fant

    JA Fant Well-Known Member

    C-J pre-amps and amps are the best IMO.
     
    bluemooze and macster like this.
  12. Myles B. Astor

    Myles B. Astor New Member

    Location:
    New York, NY US
    Hi Steve,

    I have owned cj preamps (starting with the PV5) and amps (starting with the MV75A1) and have never had a problem with tubes in any of the units. The only problems were with the muting circuits in Premier 3s/PV5s and once had a resistor go in an 8 year old MV75 that was replaced immediately without charge.
     
    macster likes this.
  13. Myles B. Astor

    Myles B. Astor New Member

    Location:
    New York, NY US
    One tube you might want to check out that's not hideously expensive are Telefunken 7DJ8s.

    Myles
     
  14. macster

    macster Forum Resident

    Location:
    San Diego, Ca. USA
    I've own this same setup for a number of years (5 -8) and only last year decided to let go the MV75A1's. My change out schedule for the tubes was every two years whether they needed to or not. I still own the PV-5 which is mated to a MF2500A. The PV-5 is scheduled to be retubed next year, with tubes from Upscale audio.

    M~
     
  15. TONEPUB

    TONEPUB Forum Resident

    Location:
    Portland, Oregon
    This is incorrect...

    My ACT2 series 2 just logged 14 thousand hours on it's first set of tubes, so I would hardly call that "hard on tubes".

    The only reason CJ and ARC got this reputation was because about 15 years ago they got some bad tubes from both Russia and China that were problematic. It was the tubes, not the gear.

    Here's the 6922's I got from Kevin 6 years ago for my PV-12 and they are still running strong:

    http://www.upscaleaudio.com/Mullard-CV24936922_p_610.html

    A few more bucks, but will give your preamp a slightly more neutral, less warm sound. More bass slam and dynamics, quieter as well...
     
    sushimaster likes this.
  16. Puma Cat

    Puma Cat Well-Known Member

    Location:
    East Bay, CA
    6922/CV2493's in a PV12? Is this a 12AU7 equivalent, which is the C-J specification for this preamp? Or is this a tube that was in the phono stage? I'm running NOS Mullard CV4003s (a military designation for the 12AU7) in my line-stage PV12 and now that they've run in a bit and have been cryo'd are quite impressive. Better depth, bass control, image solidity, "full-bodiedness" and punch than RCA Clear-tops. Cryogenically treating them gave them the air and ariticulation on top that they were lacking a bit before treatment (though I still preferred them even then to the RCAs). Anyway, it's interesting either way as both the tubes referenced above and the one's I've settled on are mil-spec Mullard "CV-series".
     
  17. TONEPUB

    TONEPUB Forum Resident

    Location:
    Portland, Oregon
    Good one, now I'm incorrect! Yes, the CV4003's are the ones I got from Kevin, sorry about that.....

    Nice improvement in the sound though!
     
  18. Puma Cat

    Puma Cat Well-Known Member

    Location:
    East Bay, CA
    Couldn't agree more. Are you in Munich for the show there?
     
  19. bluemooze

    bluemooze Forum Resident

    Location:
    Frenchtown NJ USA
    I bought my CJ PV-12 new 20-something years ago. Still has the same tubes in it. FWIW :)
     
  20. BIGGER Dave

    BIGGER Dave Forum Resident

    Not to derail this thread, but there are TWO CJ MV-55 amps available locally, one listed at $1,200 and the other has no price listed in the ad. Can't get the owner of the second amp to respond to my inquiries for the price! Very frustrating.
     
  21. bluemooze

    bluemooze Forum Resident

    Location:
    Frenchtown NJ USA
    Links please? :)
     
  22. BIGGER Dave

    BIGGER Dave Forum Resident

    PM sent.
     
    bluemooze likes this.
  23. allied333

    allied333 TUBE AMPLIFIER REBUILDER - inquire

    Location:
    Fenton, MI
    6922. Best I heard is RCA 6922 with Made in Germany printed in black ink on the box. These are early Siemens 6922 with some stating made with special .o28 grid wire. Stunning tube.
     
  24. sushimaster

    sushimaster Forum Resident

    Here's my Conrad Johnson PV-10BL
    I think I need to hit up Kevin Deal for some tasty Mullard or Brimar CV4003/12AU7 Cryod tubes.

    [​IMG]
     
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  25. allied333

    allied333 TUBE AMPLIFIER REBUILDER - inquire

    Location:
    Fenton, MI
    Brimar or Pinnicle 13D5 are better than Mullard
     
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