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    m-125 input impedance

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    buchela

    Posts : 30
    Join date : 2011-03-09

    m-125 input impedance

    Post by buchela on Fri Jul 08, 2011 5:11 am

    what would be the ideal preamp output impedance that can make the m-125 monoblocks happy.

    Bob Latino
    Admin

    Posts : 2414
    Join date : 2008-11-26
    Location : Massachusetts

    Re: m-125 input impedance

    Post by Bob Latino on Fri Jul 08, 2011 6:36 am

    Hi,

    The input impedance of the M-125 is 270,000 ohms. The general rule is that the output impedance of the preamp should be at least 1/10 of the input impedance of the amp. So by this "rule" any preamp with an output impedance below 27,000 ohms would work fine.

    There is no real "ideal" preamp output impedance to work with the M-125's. Going lower than 27,000 ohms on the preamp's output impedance won't have any real affect on the sound of the M-125 monoblocks.

    Bob

    tubes4hifi
    Admin

    Posts : 1292
    Join date : 2008-11-30

    Re: m-125 input impedance

    Post by tubes4hifi on Sat Jul 09, 2011 3:47 pm

    Bob is correct, input impedance is rarely an issue except with a few certain solid state amplifiers which have a very low input impedance (under 10k ohms!!) All tube amps have very high input impedance, and almost all preamps have an output impedance of under 1K ohm.

    GP49

    Posts : 735
    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: m-125 input impedance

    Post by GP49 on Sat Jul 09, 2011 6:42 pm

    tubes4hifi wrote:... almost all preamps have an output impedance of under 1K ohm.

    And the GLARING exception? The Dynaco PAS at 1000Ω.

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