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Old 07-20-2009, 03:48 AM
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Default Cosmic amp question

First of all, let me say I am in love with the build quality and sound quality of my HeadRoom Cosmic Reference amp bought from a fellow head-fier I've recently started getting into DIY but I find it hard to even build a cheap Cmoy for fear of not using it when I already have this great little amp!

With this newly-acquired skill, I would like to fix my only quarrel with the amp; it was originally bought in 2003 and after all those years the volume pot is a little bit "scratchy" and there is a slight channel imbalance at low volume. I was wondering if Tyll or anyone else knowledgeable about this amp could point me to a replacement volume pot, or at least the impedance (10kΩ, 100kΩ) and pinout of the original pot.

Thanks in advance =]
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Old 07-20-2009, 05:08 PM
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The scratchyness is because we don't want caps in series with the signal chain at all, so there's a little DC flowing through the pot. When you turn the pot, surface noise modulates the DC and creates signal: the scratchy sound. So the pots not really bad, and there's no problem unless you're turning the pot.

The channel imbalance at the low end is just "one of those things" with that pot.

I'd suggest you don't worry about it, it's got it's problems, but otherwise it's a good sounding pot.
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