From: "Terry King" <>
> Walter, a more remote possibility to check is the presence of DC
> offset or leakage on the signal lead. If a capacitor in the preamp
> output circuit is 'leaky' then a DC voltage will be present on the
> output signal. Even a small discontinuity in a connector or movement
> in a cable shield can create noise.
>
> Test this by measuring the DC voltage across the connector while
> plugged in your normal configuration. It should be very small (less
> than .01 volts) or unmeasureable, using a typical small digital
> multimeter.
>
> Try a temporary 'fix' by inserting a good .1 microfarad capacitor in
> series with the signal. If the crackles are gone, you found the problem.
>
> IF this is the problem!
Note that many small pre's, and most walkman MD's and so on do have DC
on the input, and it belongs. That's the plug in power. So, before
rejecting some piece of equipment, see if the DC belongs.
And note that even if the DC does not belong, it takes making and
breaking a connection to get the crackle. Fix the cause of the making
and breaking the connection first, or fixing the DC will not fix all
your problem. You will just have gaps in the recording instead.
Tossing a stray cap in the input without thinking about it can mess up
frequency response, etc. Do not do this as a routine first thing for static.
Walt
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