2. amps-preamps
  3. 1036073540

Floating the Ground

My B&K Ref 30 is sick and not working quite right. I am awaiting the arrival of a new Ref 50 but they keep delaying the shipment.

One of the problems is a terrible hum in my speakers coming from the preamp. It doesn't matter if the ref 30 is on or off, if it is plugged into the power source (wall or conditioner) the hum immediately starts.

I think floating the ground on the Ref 30 would eliminate the noise but I don't know for sure if there is a downside to doing this until the new Ref 50 comes in.

Any power experts out there?
bundy
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Do you have a cable tv line? If so there is a chance this is creating the ground loop hum. You could try floating the ground, from my experiences, this helped, but didn't eliminate the hum altogether. You could try one of those cable ground isolaters (like the Mondial Magic Box) also, if you have a cable line. I found more success with the Magic Box than with floating the grounds.

Good luck,
John
sdcampbell
2,136 posts
 
I can't offer a lot of help beyond what John has suggested, but I do have one thought: try installing the ground loop isolator (GLI) that Radio Shack sells before you spend $100 on the Mondial unit. My son had a hum problem similar to the one you describe, which we determined was caused by the input from the TV to the pre/pro. The Rat Shack GLI eliminated the hum when it was installed -- and I think it cost less than $20.
bundy OP
127 posts
 
I had that problem too and a ground loop breaker fixed that. Now the problem starts and stops when I plug in the REf. 30. Like I said, I think there is a problem with the unit and it is being replaced. My dealer also had a buzzing problem when he hooked it up.
More to discover