Stepper sound in speakers

I have been using my blue dot 950 for 2 years after going through the "hiss" issues of past. The final fix was quite good. However, just yesterday I noticed increased "hiss" from my Klipsch RF-7s. I quickly checked calibration which was done at -7db master and equated to about -4db on the mains -1db on the center and about +3 on the side and rear surrounds. After calibration I still noticed the hiss from about 10 feet away which is listening position. Also I noticed an audible click each time I changed the trim or master volume level. The stepper sound is prevelant from -55db up to reference of -7db where it grows significantly (which is understandable at that level).

Any ideas on the next steps to trouble shoot this increased hiss. Also, I noticed a slight hum coming from the mains also. After unplugging the cable connection it still persists.

Thanks,
Scott

If you have gain controls on your power amps, you might try setting the trims on the 950 to zero across the board, and performing your calibrations with the pots on the power amps. It really sounds like you have a gain structure problem, and the Klipsch speakers are probably pretty efficient. My horns are 106db/watt efficient and the 950 is quiet enough for even these hyper efficient speakers with proper gain structuring.

The "zipper" sound of the volume control when changing volume is normal for electronic volume controls but is undoubtedly being aggravated by your gain problem.

Thanks Soundhound. I found that by using a "cheater plug" on my Acurus RPC-120 power strip connected to an Acurus A200 that I elimated the hum as well as the zipper noises. I agree, it sounded like the gain was way over done before. Not sure why breaking a ground loop would also reduce the apparent "hot" gain.