i leave mine at -30db not because of your post but because i thought it was the setting i wanna run it at in my ssytem with a behringer control 2 usb, i don't hear any noiseI got another A20a from the same seller (amazon.de). This time it is the updated version.
- no relay clicking
- higher power draw. It consumes 2W more power (idle: 3W vs 1W, music: 6W vs 4W).
- a sticker with a serial number underneath
- the previous A20 had an extra hole on the back panel (right side to the 15V DC output) which was masked with some black sticker. This newer version doesn't have such hole.
- and one more thing:
My audio chain is like so: PC -> DAC -> A20A -> Speakers. With the old A20a, speakers are near dead-silent when not playing a sound. But with the new one, there is a constant electronic noise that is audiable and quite annoying at 2 meters from the speakers even at -20db at the amp (it becomes inaudible around -30db).
The noise goes away when I unplug the PC, but that defeats the purpose. The A20a is the only variable here - even the cables are the same.
I tried turning the internal voltage regulator to the max, as suggested earlier in this thread, but that did not change anything.
Any idea what can cause that difference in noise or how to get rid of it?