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Am I safe to run my SS amp with no speaker load?

Discussion in 'Amps and Cabs [BG]' started by natrab, Nov 10, 2004.


  1. natrab

    natrab

    Dec 9, 2003
    Bay Area, CA
    I searched this question but couldn't find a clear answer. I have my Mesa M-2000 and it only can handle a 4-Ohm load. Occasionally I like to hook up my "big rig" which ends up with two 2Ohm loads (perfect for my QSC 3402).

    Now can I be safe just using my M-2000 as a pre-amp, without any speakers plugged directly into it? Or do I have to bring along something to match the impedance. I know this is true for tube amps, but what about SS.
     
  2. 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
    I don't think it's a problem with SS amps.
     
  3. Tim__x

    Tim__x

    Aug 13, 2002
    Alberta, Canada
    The real problem lies in the output transformer, 99.999999% of SS amps have no output transformer. In other words, you'll be fine.
     
  4. chunky

    chunky

    Nov 3, 2004
    Portland Oregon
    I agree with these fellows.
     
  5. Tritone

    Tritone Supporting Member

    Jan 24, 2002
    Santee, America
    No problem running the M-2000 without speakers. As a matter of fact, it's designed to do that for direct recording per the manual.
     
  6. Frank Martin

    Frank Martin Bitten by the luthiery bug...

    Oct 8, 2001
    Budapest, Hungary, EU
    Tube power-amp sections: only use the recommended loads (usually 4-8 Ohms), NEVER use without a load;
    SS: use more than the recommended minimum load or dont use a load. Safe without a load, usually
     
  7. 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
    As others have mentioned, with a solid-state amp, the load impedance only has to be equal to or greater than the specified minimum.

    Here are three examples of how that works with amps of typical minimum load impedances (8, 4, and 2 ohms) and nothing connected:

    Amp's specified minimum load impedance: 8 ohms.
    No load connected = infinity ohms.
    Infinity ohms > 8 ohms.
    Verdict: Okay

    Amp's specified minimum load impedance: 4 ohms.
    No load connected = infinity ohms.
    Infinity ohms > 4 ohms.
    Verdict: Okay

    Amp's specified minimum load impedance: 2 ohms.
    No load connected = infinity ohms.
    Infinity ohms > 2 ohms.
    Verdict: Okay