I have a new ST-70 that I built up with the VTA board. Upon testing, all three 6SN7 tubes lit up. So I removed them and installed the rectifier tube and the two new 6CA7 output tubes in the left channel and was able to bias them to .40 volts no problem. I then removed those and put the two other new 6CA7 tubes in the right channel and when I started the amp up as the tubes came up the volts quickly rose over .60 volts so I shut it down quickly. I thought it might be the tubes so I switched them out with the ones I used for the left channel and same problem. So I removed all the tubes and powered it up and got -47 to -50 DC volts on pins 5 and 6 of all 4 tube sockets.
Some help would be appreciated as I am not an expert at this. I will try to attach a picture of the internals to see if something is off and I just can't see it.
Dave in TX