Vintage Park Marshall Preamp Tubes recommendation

Discussion in 'Amps and Cabs' started by skylabfilmpop, Jan 16, 2008.


  1. skylabfilmpop

    skylabfilmpop Silver Supporting Member

    Messages:
    516
    Joined:
    Jun 20, 2006
    I have got a great sounding '71 Park 75 but want to tweak the tone a little. Sometimes the midrange is a little strong under a MIC. The culprit could be my G12M25 loaded Bogner 2X12 (@ 8 ohms) having a Plywood back, or maybe that the amp has been tubed with sylvania big Bottle 6CA7 power tubes. I am hoping some preamp tube juggling might help me out. Which of the following preamp tubes and in what placement would Y'all think might deaccentuate the mids a little or optimize the tone?

    Telefunken 12ax7/ecc83 (I have 3)
    RCA 5751
    RCA 12ax7
    JJ 12ax7

    Other Recommendations?
     
  2. Blue Strat

    Blue Strat Member

    Messages:
    29,836
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    Try them all, one at a time, starting with the V1 socket. Keep the one you like best there, then move on to V2 and V3.

    No one knows what you'll like or what the rest of your rig sounds like, so using your own ears is the best option.
     
  3. FloridaSam

    FloridaSam Member

    Messages:
    4,215
    Joined:
    Oct 5, 2006
    Location:
    Under a palm tree
    My Plexis always sounded best with a Telefunken in the PI spot and Bugle Boy Amperex in the others.
     
  4. sickboy79

    sickboy79 Member

    Messages:
    9,059
    Joined:
    Aug 17, 2006
    Location:
    Chicago
    Agree. RCAs are some of my personal favorite 12AX7s. I'd start with trying that in V1. But, use your ear - it will never steer you wrong!
     
  5. Roe

    Roe Member

    Messages:
    6,777
    Joined:
    Jul 12, 2005
    Location:
    tromsoe, norway
    put a telefunken in v3. don't just listen to the sound of it, but pay close attention to the PI and power amps response. the rca might work in V2
     
  6. ROKY

    ROKY Member

    Messages:
    6,871
    Joined:
    Mar 2, 2004
    Midrangey Park 75, eh ?

    Well, first of all, congrats on owning such a cool amp; always wanted one
    of those .. they came from the factory w/ KT88s, no ?

    I don't think the Sylvania's are contributing to the middiness. Those, like
    the 88s should be a comparatively bassier tube than an EL34.
    The greenbacks are midrangey(duh..) and you didn't say what mic you're
    using .. an SM57 for example is nasally, but is a staple in miking guitar
    cabs .

    Being that your amp is a '71 it might very well be similiar to amps of the
    period that are by most accounts quite bright/upper mid heavy, etc.

    I'm pretty sure that the Park 75 was not much different than the 1987
    lead amps 'cept for the KT88s in the pwr section.

    You might also consider looking at changing the slope resistor if you want
    to flatten the mids a little .

    Good luck with that cool amp.
     
  7. electronpirate

    electronpirate Member

    Messages:
    2,935
    Joined:
    Jul 27, 2005
    Location:
    The Jewel of the Rockies
    Question:

    If you have dialed in the tone, but it sounds midrangey through a MIC, isn't the problem the MIC (or the EQ at the board?), not the amp?


    EP
     

Share This Page