Page 1 of 1

peavey triple x high bias reading

Posted: Wed May 29, 2013 5:01 pm
by mrkrausman
This amp has bias test sockets in back. It has 6l6s mounted. When I put my meter in probes it measures 55v DC not millivolts. What is happening here? Thanks in advance.

Re: peavey triple x high bias reading

Posted: Thu May 30, 2013 5:57 pm
by joey
mrkrausman wrote:This amp has bias test sockets in back. It has 6l6s mounted. When I put my meter in probes it measures 55v DC not millivolts. What is happening here? Thanks in advance.
If memory serves me correctly from the last one I serviced a while back, that test point only reads the bias voltage applied to the grids of the output tubes, (-55v sounds about right, +55 depending on polarity of the probes) it doesn't indirectly measure plate current via the cathode like the typical 1ohm resistance method or a bias probe would. If you take out the output valves you will still measure the same thing. If you have a probe, just set it that way, or what ever your favorite bias method is. That test point was not meant for user serviceability though, as far as I remember that is.