Can someone explain MOSFET to me??

Discussion in 'Amps and Cabs [BG]' started by lookjojoisplaid, Dec 27, 2005.

  1. westland


    Oct 8, 2004
    Hong Kong
    metal oxide semiconductor field effect transistor ... it's voltage regulated (like a tube) rather than current regulated (like a transistor).... I think this is supposed to make it easier to include in amp designs
  2. The 0x

    The 0x

    Aug 24, 2003
    Timonium, MD
    MOSFET-A marketing ploy created by several amp companies, claiming that they sound "just like tubes, but with solid state reliability!" :rolleyes:

    Sorry, had to vent...
  3. lookjojoisplaid


    Oct 17, 2005
    San Diego
    so what the big man upstair is lying to me and really sound maybe a little better than solid state?
  4. Mcrelly


    Jun 16, 2003
    Minnesota, USA
    Mosfet designs have sounded better to me than others, but not as nice as tube. but some new switching amps are starting to sound pretty nice.
  5. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    Without being reactionary, MOSFETs are slightly closer to warm sounding than other solid state schemes. Not tubey, but smooth.
  6. fdeck

    fdeck Supporting Member

    Mar 20, 2004
    Madison WI
    HPF Technology: Protecting the Pocket since 2007
    MOSFETs have similar overload behavior to JFETs or tubes in class-A circuits, i.e., preamps. But they are rarely used in preamps. When used at the output stages of mainstream power amps employing high open loop gain and linear feedback, one would expect no sonic difference between MOSFETs and bipolar power transistors.

    What makes a tube power amp sound like a tube power amp is the much lower open loop gain, giving rise to higher distortion and "soft" clipping response.

    Thus claiming that MOSFETs sound like tubes is indeed a marketing ploy.

    Case in point, my DIY preamp design uses MOSFET op amps that are rigorously linear up to a hard clipping limit.
  7. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    A MOSFET is a transistor, so it is solid state.
  8. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    If the amp is accurate, whether it has MOSFET or bipolar transistors, it will sound warm if the input signal sounds warm.
  9. seamonkey


    Aug 6, 2004
    Whatever "warm" means :)
    There are many good, accurate, affordable, solid state amps on the market today.