[JSVice]

I have nothing constructive to say, except that "bar hum job" reminds me of
something Ebenezer Scrooge might say.

--
Thanks,
John
"hank alrich" wrote in message
...
I'm helping folks who have a sports bar get some of their audio action
working better. Following info from RAP in other ground problem threads
I've determined that the ground is good and that the AC to the closet
with the CD changer, Onkyo receiver and a stack of DishNet video
receivers is good, too.

There are two hum-related problems he

1. A certain amount of hum seems related directly to the Onkyo receiver
in that about 3.5 volts is showing between the chassis of the CD player
and the receiver (probing at the ground collars of their respective RCA
connectors) when the system is first started cold after being turned-off
overnight. As it warms up that rises, to as much as 12 volts. When the
CD player AC power was sourced from an outlet on the back of the
receiver I measured 10.5 volts at cold start, and lord only knows what
it must have been after warming up. When I hooked the CD changer's AC
cable to the same power strip feeding the rest of the gear in the closet
the voltage dropped to 3.5 cold.

Is this a sign that the power supply filter caps in the receiver are
leaking, and leaking more as they heat?


2. There is a ridiculous amount of hum coming via the audio feeds from
the DishNet video recievers, fed to the Onkyo receivers audio inputs.
Yet there is no comparably appreciable voltage showing between those
chassis; measuring again RCA's-to-RCA's I see single-digit millivolts.

I plan to go back with the MIO and feed audio from the video receivers
to SpectraFoo to see if noise associated with those audio feeds is
actually being delivered along with the intended audio, i.e., if that
hum is not simply inter-component ground related, but part of the
"signal".


I cheerfully and gratefully solicit advice and commentary. At this point
they cannot feed audio from the video receivers into the house speaker
system driven by the Onkyo, at all, and can stand to play CD's only with
the bass level control on the Onkyo turned way down. I'm figuring they
need to replace the Onkyo, for starters, but I'm not convinced that's
going to take care of the video-related audio noise problem.

--
ha
Iraq is Arabic for Vietnam