Too Much Gain from R17

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Too Much Gain from R17

Postby jwschaff » Wed Jan 17, 2007 12:14 pm

I recently completed three J99 preamps using John Hardy 990cs. All three preamps work just fine except that the gain trim control (R17) on one of the three has a much wider level of gain than the 5db specified in the documentation. When swept fully clockwise, I get so much additional gain that I can go from a very quiet counterclockwise position to ear-splitting feedback when rotated to the fully clockwise position.

On the two other units, the gain trim seems to work just fine--offering a comfortable gain rise from counter- to clockwise. Everything else seems to work fine, and I do not see anything that looks out of the ordinary.

Any ideas?
Dr. John
Token Creek Recordings
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Postby jwschaff » Thu Jan 18, 2007 2:53 pm

No thoughts on this one?!?
Dr. John
Token Creek Recordings
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Postby tpryan » Thu Jan 18, 2007 8:00 pm

Make sure that R17 is 1K and not 10K.
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