On July 21, 2007 at 03:52, Ernie Bornn-Gilman said...
I can see some comedian out there getting ready to tell
you: Noise? Filter it out! just hang a 100 microfarad
capacitor across each audio input!
Call Rotel and raise hell. It is entirely unreasonable
to have to connect a separate ground cable between an
RS232 controller and the device it's controlling. If
that were necessary, they would provide a pin for it in
the cable. Actually, there IS a ground wire in the cable,
so what the heck?
But also check for parallel runs of anything near anything
that could be inducing that noise.
Just the usual rack spaghetti.
What happens if you ground the switcher to the RP6 but
not to the receiver? This makes no sense but you should
try it.
when I remove the ground from the receiver the high pitched noise dissapears so I did not even bother grounding it at the switcher.
Does any of this noise show up as artifacts on the screen?
What happens if the screen is off, or better yet not
connected? Does the screen have a three-prong power plug?
And, of course, its media box? Maybe if you ground the
RP6 to the TV media box instead of to the Rotel....
I tried grounding it to every component with the same result.
No effects on the video whatsoever.
I thought about mucking with the EQ adjustments on the gefen switcher. I know nothing about that EQ circuit but hey, I can always fiddle with knobs!
I was also going to explore ground lifting the devices one at a time to see if I could tackle the crosstalk without supplemental device grounds. Now that I recall, I think the Gefen tranformer may use a grounded plug. The rack mounted power distribution is hard to see in the rack and I may have just assumed that it was a two pronger. Its not like I have not had power supply issues with Gefen before.
