12ax7s in vibroverb custom???

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by coolhand78, Jun 4, 2008.

  1. coolhand78

    coolhand78 Supporting Member

    Messages:
    3,578
    Joined:
    Oct 27, 2007
    Location:
    Melbourne, Australia
    I'm wanting to play around with the configuration of the
    preamp valves in the 64 vibroverb custom...

    I have JAN Philips 7581A's in the power section and a JAN 5AR4/GZ34 rect.

    I have at my disposal 2x NOS RCA 12Ax7's (which i use for the vibrato channel) 2 x tung sol 12ax7 reissues, 2 x JJ ECC803's and 2x NOS JAN 5751's

    I do particularly like the RCA's but what about the other positions?

    I'm also considering taking out the Valve from V1 and see how that sounds...

    I crank the amp to about 8 when i play and am not particularly concerned with bringing down the volume... i find it difficult to describe the tone im after but it's somewhere between SRV/Clapton/Hendrix/Ford (who isnt..?)
    I have a large pedal (see sig for list)

    What do people recommend...

    thanks for your help...

    L.
     
  2. Gene

    Gene Member

    Messages:
    1,624
    Joined:
    Jun 22, 2007
    Location:
    New York City
    I would definitely go with the NOS RCA for the preamp. Just my preference of the choices you show.
     
  3. phsyconoodler

    phsyconoodler Member

    Messages:
    4,351
    Joined:
    Jul 11, 2005
    Location:
    calgary canada
    To get closer to SRV tones you need a mid control.Pinning the mids on a blackface gets you some righteous growl.The Vibroverb is different,but has something special that blackface amps don't have.Try a different set of power tubes.I like the TAD 6L6 short bottles.They have a unique breakup.
     
  4. coolhand78

    coolhand78 Supporting Member

    Messages:
    3,578
    Joined:
    Oct 27, 2007
    Location:
    Melbourne, Australia
    I'm mostly concerned with the V1 and V5 positions, and whether people would recommend JJ's or Tung sol's or 5751's in these positions? (I should have been more specific...)

    I have the RCA's in V2 & V4, and i like them there... i'm also happy with the 7581a's...

    also, will removing the V1 tube reduce volume??

    cheers

    L.
     
  5. GearHeadFred

    GearHeadFred Member

    Messages:
    1,657
    Joined:
    May 4, 2007
    Location:
    San Diego, California
    Removing V1 will increase gain slightly (on the Vibrato channel), and render the normal channel non-functional.
     

Share This Page