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Help...hum issue with new preamp

Hi goners, I have just switched preamps from an Aesthetix calypso sig to a Supratek Cabernet and I am now getting a  decent hum from the balanced connections from my Atma-Sphere monos to the Supratek where as I did not get it at all with the Aesthetix. Now I had an old set of single end cables that I used with the Supratek to troubleshoot and the hum was gone. The only thing I can think of is that since the Supratek is not truly balanced it must be causing an issue, as we know the Aesthetix is truly balanced. In any event I want to keep my xlr connections because of length. No I have not contacted Mick from Supratek yet as I'm hoping this can be resolved easily. .Any help would be appreciated. Thanks so much. 
barfbag

Showing 2 responses by atmasphere

atmasphere's avatar
atmasphere
11,569 posts
 
Maybe Ralph, the owner of Atma-Sphere, will see this thread and respond.
Indeed I did.

I'm pretty sure all that is happening here is that the Supratek has no internal connection on its XLR (since its a single-ended preamp) between pin 1 and pin 3. As a result, pin 3 is picking up noise and the amps are amplifying it.

A jumper installed between pin 1 and 3 on the XLR inside the preamp should sort it out.
atmasphere's avatar
atmasphere
11,569 posts
 
Couldn't he do the same thing at the end of the two XLR cable connectors that plugs into the preamp? Solder a jumper wire from pin 1 to pin 3 of the female connector.
Yes, he could. I doubt the preamp is in warranty FWIW; if it is I would consider having the manufacturer fix the oversight, as that's what it is.
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