Thanks for the response. It's good to figure out what is going on. I bought the amp used on Audiogon and it came with 6550 and KT-120 tubes. I don't know how many hours are on them.
VSi60 Bias Adjustment
Today I checked the bias settings on my VSi60 and I get a 0 millivolt reading from one of the tubes. The amp was warmed up for 30 minutes before the test but was not connected to my speakers while testing. The other 3 tubes show a 60mv reading.
To try to see if it was a bad tube I did try another tube set (KT-120) in the amplifier and I got the same result. So it's probably not a bad tube.
I'm fairly new to tube amplifiers but I have had the VSi60 for a couple of years and I do like it.
My question is what do I do? I cannot fit the plastic screwdriver that came with the amp into the slot of the bias adjustment of the tube that needs adjusting. Should I unscrew the trim plate on top and make a bias adjustment? Or is the amp broken and in need of service? The amp sounds fine but I would like to know what's going on.
To try to see if it was a bad tube I did try another tube set (KT-120) in the amplifier and I got the same result. So it's probably not a bad tube.
I'm fairly new to tube amplifiers but I have had the VSi60 for a couple of years and I do like it.
My question is what do I do? I cannot fit the plastic screwdriver that came with the amp into the slot of the bias adjustment of the tube that needs adjusting. Should I unscrew the trim plate on top and make a bias adjustment? Or is the amp broken and in need of service? The amp sounds fine but I would like to know what's going on.