Originally Posted by forgottenviking
I too thought I should receive "ground" noise from the RCA's but didn't.
And I assume you had the sub's volume control turned up?
I do this test often with my guitar
. I was plugged into the low-level in when i did not hear any noise. That's what lead me to believe maybe those inputs are not the correct ones.
They (the RCA jacks) are the correct ones for line level signals.
If I run speaker wire into the speaker clips and try this test I should receive ground hum correct?
Much less likely, because there is a resistor divider to scale the amp's level back down to preamp level. Probably 30 dB atten, and a lower impedance, too, so not as easy for the finger to impart hum.
I told the client that I believe what I set up was correct (except or the FL and FR being plugged into the RL RR outputs) and that something might be wrong with the sub.
Would not be the first time.
There are some manuals of "cousin" models here
. The ARPR1010 has similar looking cosmetics anyway.