60HZ hum on my Lyr 2 headphone amp

[r042wal]

I'm looking for some trouble shooting opinions.

I have a McIntosh C48 preamp. I took the #2 RCA low level output, attached a good quality 25' RCA cable to it, then plugged it into my SB-2000 Pro subwoofer. Every works like a charm.

I did not want to run a long headphone cable across my living room for my headphones so I put an RCA "Y" connector in at my sub and split it off to my Lyr 2 preamp. This way I have everything beside me when I want to use my headphones.

If I turn up the gain on the headphone preamp more that 25% I get bad 60Hz hum. Any suggestions? There is no ground on the Lyre. I am wondering what would be the best way to troubleshoot this? It I disconnect the Lyr from the chain, there is no problem with the low level signal going to the sub, it's perfect.

TIA for any suggestions

 

[NTK]

A bit on the expensive side, but should work.

CI-2RR | Jensen Transformers

The unbalanced stereo design begins with gold RCA connectors to ensure optimal signal transfer. These are housed in a rugged steel enclosure that is fitted with screw-down flanges for easy installation in racks, under shelves or attached to cabinetry. The magic inside comes from two high...

www.jensen-transformers.com

Jensen CI-2RR IsoMax Stereo Audio Isolator & Hum Eliminator

The Jensen Iso Max CI-2RR is a passive two channel RCA audio ground isolator designed to eliminate hum and buzz caused by ground loops in the most demanding audio systems.

www.markertek.com

 

[r042wal]

Thanks! I ordered one from Parts Express and will give it a try. Do I want it after my "Y" connector before it goes into my Lyr 2?

 

[NTK]

Thanks! I ordered one from Parts Express and will give it a try. Do I want it after my "Y" connector before it goes into my Lyr 2?

Yes. That way it will isolate the Lyr 2 from the rest of your system (since you sub doesn't seem to have any ground loop problem with your Mac and therefore no isolation is necessary between them).

 

[r042wal]

@NTK I just wanted to update the group after reciving my Jensen ISO-Max. This little box worked like a charm and killed any hum I had. I a'm so thankful for the wonderful suggestions. Cheers from Canada