ARC ref 110 tube bias prob

All is going well but the last two tubes (master and slave) are showing weird readings.

The master shows no reading and reading 16.76 volts DC (not 0.65mVDC!) on my Fluke. The slave is showing a negative rating (-20mVDC).

The tubes are all good (swapped them over) but any tubes in that position do the same.

Anyone know what’s going on?

willmarchant11-14-2022 5:24pm

ghdprentice Details Discussions Posts This discussion Message User 8,084 posts 11-14-2022 at 05:33pm Copy Comment URL Report Comment Edit Delete I would call audio research. In the past I have done this and talked with… the tech. Or email. But calling is quicker.
jjss49 Details Discussions Posts This discussion Message User 6,612 posts 11-15-2022 at 01:01am Copy Comment URL Report Comment Edit Delete i have that amp, is that particular one new to you? seems like when the last set of power tubes went (perhaps in the hands of the prior owner), they took out a biasing resistor in that quadrant, which will likely require the amp traveling back to minnesota
fsonicsmith Details Discussions Posts This discussion Message User 987 posts 11-15-2022 at 02:02am Copy Comment URL Report Comment Edit Delete Yeah, I know I lent you my 2 cents in your original thread but I was wrong. I think only a circuit problem like the above referenced resistor could explain your Fluke reading.