Could be a bias resistor out of spec or bad pot.
Problem with biasing
Hi, I have a citation 2 and recently re-tubed with gold lion kt88. I noticed that tube 8 was glowing a little more than the others. So I checked and it was 1.7 volts. My other tubes are 1 volt. Bias 1.68 volts is the lowest I can get which is still too high. Anyone ever have this happen?
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- 9 posts total
Try switching tube positions. Does the bright glow move? If not refer to @oddiofyl, if it moves replace the tube. |
Most likely a bad tube. Swapping tubes will tell you if it is the tube or something internal. a bias resistor has been suggested and that would indeed explain the reading but these resistors should last a lifetime. Running at high bias current will ruin the tube, but it may already be there. If indeed it is the position and not the tube, then don't run the amp until you get it fixed unless you have a big tube budget. jerry |
- 9 posts total