Just replaced shunt regulator board which wasn't working. All resistance and voltages est with 10-15% or better, except filament is a bit low. Left sound sounds great. Right channel is dead except for hum/buzz (120 hz???). Every thing measure identical side to side. I have swapped inputs, tubes, outputs and it is not the feed from turntabl4, tubes or preamp/amp/s[eaker/cables down stream. I resoldered the RCA's. Any clues what to check next?
