Ampeg SVT-3 plate voltage - how does it function?

Discussion in 'Amps and Cabs [BG]' started by tonynoriega, Mar 17, 2006.

  1. tonynoriega

    tonynoriega Supporting Member

    Jun 26, 2004
    Tampa, Florida
    I just read reviews on the SVT-3 Ampeg, which I own and use, and three guys talked about being able to control the plate voltage, and what an advantage that is. I don't understand enough about amps (I just turn the knobs until it sounds like I want it to) to understand the function. Any insight would be greatly appreciated.
  2. Trevorus


    Oct 18, 2002
    Urbana, IL
    This probably isn't just an adjustment that can be made easily. It has to do witht he design of the circuit. They could put resistors in the plate source to drop the voltage to a desirable level, but this isn't for inexperienced people. you have to know tubes to fiddle with them like this.
  3. 8mmOD


    Mar 20, 2005
    I endorse & use Tech 21 pedals, Eminence loaded cabs, EMG pickups, Jim Dunlop picks & Ernie Ball Strings, BC Rich Basses.
  4. flash99


    Jun 8, 2005
    New York City
    I've had an SVT 3 Pro for 10 years and to this day, I'm not entirely clear on what this does. I think it controls the amount of signal that goes through the tubes that are in between the preamp and the power amp sections to give you more or less of a tube power amp tone. I also don't think the manual has a good description because while it claims this control "replaces the limiter" found on other amps, it doesn't do any kind of limiting or compressing. Anyone know for sure?
  5. ihixulu

    ihixulu Supporting Member

    Mar 31, 2000
    getting warmer
    My understanding was that it controls how hot the driver tube is run. In effect, at the lowest setting, the tube is given less plate voltage resulting in a "browner" tone while turning the knob to maximum increases the voltage to optimal operating level and thus maximizes the clean headroom. I think it needs to be used judiciously in conjunction with the gain and eq to actually get a good amount of grit.
  6. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    That's pretty much it. And good advice.
  7. buzzbass

    buzzbass Shoo Shoo Retarded Flu !

    Apr 23, 2003
    Jerrold, I have an older 3pro. The one with the bluish lettering. It needs new tubes, the sound has slowly degraded over time. What do I need to buy and from what manufacturer do you suggest ?