Cary Audio SA 200.2 SE power amp (latest version)

@dilatante have you swapped in completely different / better shielded interconnects and different speaker cables just for the heck of it to see if anything changes?

While my SA-200.2 was dead quiet, some other adjacent components can generate this  type of low level noise you are referring to. Worth a shot if you’ve not already checked. One of my former SS amps was ultra sensitive to picking up noise like this, fwiw. Best of luck.

@dilatante Those should work nicely and a great match with your amp too. Nice. I had the Cardas GC and CR ic cables myself and can truly appreciate what you have there. I did have to get one pair Golden Cross reterminated once.  

So, this slight remaining hum still occurs on the right channel when the rest of the system is off, correct? Does the slight hum out of the right speaker still occur if the interconnects are disconnected and you power on the amp by itself?  And does the hum start out a little louder and quiet down after the first minute or two of power-on?  hmm.. just trying to think through it with you as you already sent it back/forth.  

I had the prior non-SE version SA-200.2 and it was pretty quiet, did not hum. Nice amp. I reluctantly sold mine to go back to mono tube amps.  

Before you ship it out, make sure to plug it in to a comletely different wall plug, on a different circuit (if you can), use a different (back to stock) power cord, and different interconnects (or swap R to L), different speaker cables/connectors if you have them. Some basic troubleshooting might be worth giving a try before you send it out. Best of Luck.   

@dilatante do you have a reputable "local tech" who can go through the amp and identify the noise or possible transformer hum? Might be less shipping-damage risk and less cost vs shipping it back to Cary if you plan to fix it. I remember my SA200.2 was a beast at 87lbs. Hope you can get it resolved. Its a neat amp. Best of luck.  

@dilatante do you have a different pair of working speakers and different speaker cables you can test with this amp?   

This is a bummer learning more than a few of you experienced this humming issue on the non-ES and newer ES models of the SA-200.2  Mine was dead quiet, and reluctantly sold it.  What's concerning here is the initial response from Cary. May need to escalate it further.    If I still had my amp and it did this, it would be worth pushing on Cary Audio to send a repair white-paper with instructions for local service techs to help isolate, test, and fix this so called "oil films coating" connector issue. There may be a better way to get this coating off of the connectors, IF this is truly the root cause of the hum problem.   

At one point I thought about re-trying one of the newer ES amps yet after reading this, I'll wait.  One of you here (remaining ambassadors) who still owns one of these amps might want to reach out to owner and president Billy Wright to get him to come up with a solution. The hum noise is unacceptable for new amps.  Worth fixing locally vs. shipping back and forth, nice sounding amps.

@dilatante Yes, it is weird. Did you by chance plug the new amp into the same plug as before, or a different plug, and/or possibly different routing of cables too?

Sometimes having two different power cables on top of each other or one of them close to a set of non-shielded interconnect cables can produce a hum too.