Quote:
Originally Posted by Kevin Kuehn
How does your 245 volt B+ source measure where it feeds the 470(R56) ohm resistor?
If you have not replaced electrolytic caps C3B, C3C and one or both are very leaky it would certainly have that affect of drawing lots of current, pulling down voltages and cooking the 470 ohm resistor feeding that audio circuit. C51 being leaky could cause low audio, however it alone should not pull your voltages on the 5AQ5 down that low. It's highly suspect that one of the above electrolytic caps has either not been replaced or has become shorted(possibly installed reverse polarity). Certainly you've tested the 5AQ5 for shorts.
|
I have replaced all 3 caps for C3 with brand new caps and I made sure to observe proper polarity, as for the 245V supply to R56 its only measuring about 220V for some reason.
As for the 5AQ5 tube, I've tried subbing in a known good 6AQ5 tube (as I don't have any 5AQ5 tubes, and plus I know on series string sets you can get away with upping the the tube voltage a little bit because of higher line voltages) and I get the same results.