2. amps-preamps
  3. 1043371012

BC21 preamp problem

just purchased used preamp and last nite i hooked it up;
a hum was coming from the speakers that could be heard 8-10 feet away when no music was being played. i thought it might
be a problem with the ground, do tonite i used a cheater
plug; the hum was still there and now a loud pop comes from the speakers each time i turn it on/off. in addition, my amp goes in and out of a "sleep" mode with the preamp on

i'm afraid to turn this preamp on as it might blow the speakers. this is my first experience with tubes and felt the BC 21 would be a good starting point.

i hooked up my old SS preamp and no problems.

any help would be appreciated.

my amp is McCormack DNA.5(A revision), speakers proac 1.5
cables MIT/Magnan

thanks
llkcpapfs

Showing 2 responses by sugarbrie

sugarbrie
3,854 posts
 
Is it both channels? If just one channel you could also have a poor or bad tube; or maybe just a loose tube.

Don't be afraid to also ask the friendly folks at Blue Circle.

E-Mail Angela at [email protected]

You can tell her I sent you, if you feel funny asking about a used product. (She knows who I am)
sugarbrie
3,854 posts
 
You can try for Gilbert, but Angela usually responds to inquiries even if directed to Gilbert. It is probably a lot quicker starting with her. She is an electrical engineer by training, and will definitely discuss your problem with Gilbert. It is a small shop. I think they only have 5 full time employees including Gilbert.
More to discover