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
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.
I also recommend calling or emailing Steve, (he's actually on here sometimes).  

I've known Steve since way back in the Mod Squad days.  He's a great guy and wouldn't design a product that had problems.  I think it might be something else within the interactions of your system.  If this was a problem from the design, I would think it would have raised it's ugly head by now.

I've owned a few of his products and never had any problems.
yes, call Patrick, Steve and Patrick are two of the most helpful people you will meet. Prices are fair by audio standards, and their work is top shelf reliable!

www.smcaudio.com    


such a beautiful brut you have there, I would hate to see her not working.

Call Patrick, send her to them, they will make it right! and while your at it get some upgrades,.... you WILL be satisfied.