2. amps-preamps
  3. 130973-84405

McCormack DNA 500 loud hum

So I just picked up a McCormack DNA 500 and the damn thing just hums loudly in one channel when coupled with my cyrus preamp.  I took it in and the tech said it's because the rcas aren't grounded as they enter the same Jensen transformers as the balanced connection, this can result in really bad humming.  He's going to ground them but I just can't believe that I can't run this amp stock with my cyrus preamp?  That preamp shouldn't have any problems with this amp.  Any one have detailed knowledge of these a,ps that can guide me or my technician?

malthuse

Showing 2 responses by hifiman5

hifiman5's avatar
hifiman5
1,832 posts
 
I would suggest calling Steve McCormack at SMc Audio at 760-732-0352.  Steve upgraded my original DNA-1 Deluxe to an SMc Audio Revision A+.  Fantastic amp!

I've had occasion to talk to Steve and I think you'll find him helpful and enjoyable to talk with.
hifiman5's avatar
hifiman5
1,832 posts
 
Steve may just walk you through a diagnostic process to discover the real issue.  Good luck.
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