Advice re PC for Plinius amp

Do you have a ground toggle switch on the back of your amp?
Do you hear any difference when you use it?

I'm not sure if this applies to your amp but I have been reading up on Plinius amplifiers. I have read/heard really good things about both the company and their amplifiers and I am in the market for an upgrade. In my searching I came across something about a hum problem in one of the reviews.

I found it (Google) It was stereophile :

Here is what was said:

Don't it know the words?

The first thing I heard when I inserted the SA-100 into my system was an overwhelming hum. I'd been using MIT balanced 350 interconnect for the long run between my preamp and power amp, but while in professional audio use there is (purportedly) a firm standard regarding the grounding scheme of XLR connections, this is not so for home audio cabling. The SA-100 and my reference MIT were clearly not compatible. So I substituted a single-ended run of Monster's new M100i—which proved to be surprisingly good, as well as a bargain.

Maybe this will help you out ... good luck

Got two bridged SA-100 mk3's hooked up to a used ($100) 5 KVA step down transformer. Wired the transformer for balanced (240V in/ 60+/60- out) output but the Plinius amps seemed indifferent to balanced AC. However, can't hear any hum with a stethoscope.

thanks for the ideas. Just to be clear (as I clearly was not in my initial post) the hum is not at the amp, it is back thru the system and it gets much louder when I move the amp to class A mode via its selector switch,

I am intrigued by Horseface's suggestion to move to SE IC's - I currently use balanced transparent cable IC's (15' length). I will try SE IC's.