I was going to attempt to install a Dr Tube Bias mod kit in my TSL100 head but upon getting it apart I have found another issue. R76 looks discolored and was loose in the board. I was able to pull it right off (I could have shook the board and it would have fallen off). I metered it and it and the other like it, the others come in right at the 1000 ohm rating but R76 is coming in at 9500 ohms. Before I call Joe Twist who is local to me I wanted to ask here what this resistor does, what this problem means, and if it's worth trying to continue with repairing this PCB versus my original plan of replacing the PCB with a Revision 20 board? All 4 power tubes are Mullard EL34s showing no signs of problems and I could get the amp to bias correctly but it would sometimes run away on one side and it did sound worse once that happened. I recently bought a JCM 800 2203 Kerry King which stomps this TSL in the dirt HARD. Plan was to repair the TSL and sell it but now I'm curious if the problem might be why it can't hold a candle to the JCM800? Any help appreciated.