RFI radiated from someware or through the power being supplied can sound like hiss on the output. It is above human hearing so you the hiss might sound as a harmonic. RFI power filter may do the trick. Good grounding will help. I use power isolation transformer with RFI filtering after a Furman RFI power strip. I have no hiss.
What cause tweeters hiss ?
I could hear hiss sound when i place my ears close to both tweeters (ATC SCM 11 speaker) when Denafrips Ares II is connected with interconnect (XLR or RCA) during power on/off/standby. Hiss sound disappear only until power cord is disconnected.
At first I thought it’s amplifier (Accuphase E280), then I bypass Ares II and connecting Sony CD player with RCA out to amplifier, no hiss can be heard from tweeters.
Due to curiosity, i connected my Topping D90 with similar arrangement, I could hear hiss sound until I unplugged power cord.
During the above test, music is stopped, amplifier is turned on but at zero volume. All my music source, DAC, amplifier are from the same power source/circuit with Novaris Power Filter.
Can’t hear the hiss at my usual listening spot though.
What could be the culprit that create this hiss, DAC ? Grounding Issue?