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Reged: 23/06/08
Posts: 3888
Re: Hum Problem on Ashdown Bass Amp
      13/07/11 12:26 PM
yes plugged in and powered up....


across those 3 terminals, with your negative (black) probe on the 0V pin, you should measure + 15V between the +ve rail and 0V rail, and -15V between the -ve rail and the 0V rail.

or, if you place the red +ve probe on 0V, then the opposite should be true...

essentially the polarity of the supply across those is opposite... giving a 30V differential between the 2 15V pins.

any other result means a fault in the power rail supplying the pre-amp circuitry somewhere.

possible, as Dave says, a failed Zenner Diode...

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Subject Posted by Posted on
* Hum Problem on Ashdown Bass Amp Dan LB 11/07/11 01:39 AM
. * Re: Hum Problem on Ashdown Bass Amp Folderol   15/07/11 07:51 PM
. * Re: Hum Problem on Ashdown Bass Amp ef37a   15/07/11 08:10 PM
. * Re: Hum Problem on Ashdown Bass Amp Folderol   14/07/11 07:07 PM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   15/07/11 12:41 AM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   15/07/11 01:17 AM
. * Re: Hum Problem on Ashdown Bass Amp ef37a   15/07/11 06:26 AM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   15/07/11 07:15 PM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   13/07/11 09:49 PM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   13/07/11 09:46 PM
. * Re: Hum Problem on Ashdown Bass Amp Folderol   13/07/11 09:09 PM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   11/07/11 11:22 PM
. * Re: Hum Problem on Ashdown Bass Amp Folderol   11/07/11 10:04 PM
. * Re: Hum Problem on Ashdown Bass Amp ef37a   12/07/11 04:58 AM
. * Re: Hum Problem on Ashdown Bass Amp Agamemnon   12/07/11 06:09 AM
. * Re: Hum Problem on Ashdown Bass Amp ef37a   12/07/11 06:28 AM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   12/07/11 12:40 AM
. * Re: Hum Problem on Ashdown Bass Amp ef37a   12/07/11 05:42 AM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   13/07/11 12:10 PM
. * Re: Hum Problem on Ashdown Bass Amp . . . Delete This User . . .   13/07/11 12:20 PM
. * Re: Hum Problem on Ashdown Bass Amp . . . Delete This User . . .   13/07/11 12:26 PM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   13/07/11 12:42 PM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   11/07/11 11:11 PM
. * Re: Hum Problem on Ashdown Bass Amp ef37a   11/07/11 07:27 AM
. * Re: Hum Problem on Ashdown Bass Amp Dan LB   11/07/11 07:59 PM
. * Re: Hum Problem on Ashdown Bass Amp ef37a   11/07/11 08:56 PM

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