Greetings Earthlings ! , Top of the day to everyone out there ! . I started working on the Fisher 600 A amplifier two nights ago and I replaced a missing output transformer and I rewired the output sockets last night in it for 6L6 tubes. I am using the Fisher 470-T tuner with it also. I ordered new caps and I tested the power supply , I think it was around 480 volts. I found a broken 3.3k resistor that went to the negative feedback on the 16 ohm tap of one of the output transformers, I have another OT like the one I replaced if it is bad, for now I just cut the feedback wire sense I am only using the 8 ohm tap. It has 1k grid resistors and a 1.5 k - 3 watt common grid #2 resistor , I guess my questions would be ; can I just put a 3/5 watt 470 ohm common resistor in place of the 1.5k common resistor on The wired togather Screen Grid's #2 of the 6L6 tubes and use the stock fisher bias adjustment ? Or do I need to have separate 470 ohm resistors on each 6L6 tube ? . My other question would be if leaving the 1k resistors on G1 is ok ?. I have not done this tube conversion before from 7591 to 6L6 and I don't want to do it wrong , I thought that maybe someone here has done it before or knows the right way . I do not want to change the amps design if I can help it other than changing the output tubes. Thanks !