Hi all,
I'm using this amp to power 2 speakers for a TV in a remote room and I have a problem where I can use your advice.
The setup: there is a TV in a room with two in-wall speakers. The speaker wires for these speakers run to a cabinet in a remote room. There is also Cat6 cable running from behind the TV to the same cabinet. The TV itself has 3 types of audio-out: headphone, eARC and TOSLINK. The TV is just used for streaming TV and internet radio.
I've connected these speakers to this amp in the closet, and used a simple balun to connect the headphone output from the TV to the line-in RCA connectors on the amp over the cat6 cable.
This actually works well except that when the TV is off there is a strong buzz from the speakers. As soon as I turn the TV on, the buzz disappears. The buzz is worse when using the original power supply that came with the amp (which has no ground), versus using a grounded 48v power supply that I bought separately.
I dont want to keep the TV on all the time, so I either need to eliminate the buzz (and leave the amp on all the time) or turn the amp off when the TV is off.
Probably turning the amp off is a better solution, as it would save power. (Does anybody know how much power this amp draws when there is no audio input?) But I dont see any easy way to do it. I searched for a relay that would turn the power to the amp on/off based on the presence of a headphone level signal, but didnt really find anything. Does anybody know of such a device?
Or does anybody have any advice on how to eliminate the buzz? I believe the balun is introducing the noise, maybe the cat6 cable runs near to some power cables in the wall. I thought of using either HDMI(eARC) or TOSLINK baluns but worry that if the analog signal on the cat6 has noise then a digital signal would be impossible. Any thoughts on this?
The alternative would be switching to another amp that has auto-sensing shut-off, but the least expensive ones I can find are $120+ which is more than I want to spend for solving this...
thanks for your advice...
Ron