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Humm
Denis
Posts: 163
in AMX Hardware
Hi
In my demo store, I include a NI3000 with MVP8400
When I'm connecting control cable ( RS232) between NI3000 and Rotel preamp I get a humm in sound.
The humm is present when the preamp is on or off. Power amp (Rotel) isON
Somebody can help me ?
In my demo store, I include a NI3000 with MVP8400
When I'm connecting control cable ( RS232) between NI3000 and Rotel preamp I get a humm in sound.
The humm is present when the preamp is on or off. Power amp (Rotel) isON
Somebody can help me ?
0
Comments
Rotel's are notorious for having ground hum. Try cutting the gournd wire off the RS-232 cable. (pin 5) It's probably already getting a connection to ground off the chassis.
If it still persists, try removing all the other devices connected to the Rotel one by one and see if you can isolate a possible loop through the other gear connected to it.
Good luck on this one. Ground loops blow chunks!!!
Hi Dennis,
We tend to end up with 4 or 5 RS232 devices connected an NI-4000 on some sites, and no matter how carefully we cable them we always end up with ground loops. The best solution I have found is to use RS232 Optical Isolators. These units are self powered (by the control lines) and electrically isolate the two systems. They still pass data as normal. Ground loop goes away - Problem solved!
Just Google RS232 Optical Isolator - they're fairly rare animals but worth the cost.
Cheers
Brent