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
If you are up to it, open the chassis and examine it for poor connections. The BC-21 is wired point-to-point and, if the unit has been mishandled or grossly jostled, it's possible that connections have been opened. I had a sample direct from the manufacturer that encumbered such a problem in shipment. A quick application of the solder gun fixed it.
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 bcircle@bluecircle.com

You can tell her I sent you, if you feel funny asking about a used product. (She knows who I am)