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Old 10th February 2006, 07:12 AM   #10
ulysses
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Join Date: Mar 2003
Location: Minneapolis and Wiesbaden
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Quote:
Originally Posted by Grasshopper
So I should take it out of the rack and see if it makes the same noise? I also forgot to mention that when the direct input is active there is no noise.
You could just turn off the other devices in your rack to check for possible induced noise.

The fact that the noise goes away when the DI is active is a huge clue. It means the problem is not in the amplifier itself. When you plug a cable into the DI on this type of preamp, it disconnects the input transformer. If there was hum being induced into the input transformer, disconnecting it would make the noise go away. There are other possible scenarios, but right now I think the best bets are either induced hum in the input transformer caused by a nearby field, or else a bad connection (either internally or externally) on one of the signal input legs or ground points. I assume you've already tried swapping out cables and/or snake channels?
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Roll Music Systems
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