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bias probe:need help

7/8/2003 11:38 PM
Howard	bias probe:need help Music Man Rd-110-50 w/2-6L6GC's. (Fixed Bias amp I think). Amp sounds ok so wanted to try out my Bias Probe. I set my meter to auto DC Current yet I read only .00 -> .03 mA waivering and if I switch to lower range I read .010 microA. If I measured the plate to cathode voltage correctly (250V) I should read about 40mA. The tube on the bias probe stays dark and cold. Could the Bias probe be bad? I get continuity in the red/black probes on either side of the socket/pin #8 respectively upon trying to test it. Other sockets show continuity thru to their pins. I put in a brand new Sovtek but get same thing. I do notice that one tube glows brighter than the other and tubes have never been changed while in my posession although I seldom use the amp. Any input ? Thanks a bunch. I have no other 6L6 amp to test on. Thanks......howie.

7/8/2003 11:38 PM

Howard

bias probe:need help

Music Man Rd-110-50 w/2-6L6GC's. (Fixed Bias amp I think). Amp sounds ok so wanted to try out my Bias Probe. I set my meter to auto DC Current yet I read only .00 -> .03 mA waivering and if I switch to lower range I read .010 microA. If I measured the plate to cathode voltage correctly (250V) I should read about 40mA.
The tube on the bias probe stays dark and cold. Could the Bias probe be bad? I get continuity in the red/black probes on either side of the socket/pin #8 respectively upon trying to test it. Other sockets show continuity thru to their pins.
I put in a brand new Sovtek but get same thing.

I do notice that one tube glows brighter than the other and tubes have never been changed while in my posession although I seldom use the amp.

Any input ? Thanks a bunch. I have no other 6L6 amp to test on.
Thanks......howie.

Replies:

PAULH Does this amp use transistors for d... -- 7/11/2003 6:33 PM