If the power transformer on amp #2 is giving AC voltages in the range of 400 - 428 AC from pins 4 and 6 to chassis ground then probably someone has (mistakenly) put into amp #2 a 240 volt power transformer wound for a Dynaco Mark III rather than a Dynaco Mark IV. A Mark IV power transformer should give you about the AC voltages off pins 4 and 6 (to chassis ground) that you are getting off the power transformer in amp #1. A Mark III power transformer should give you about 410 VAC off pins 4 and 6. This is the reason the bias is off on the second amp. I really feel that (as I mentioned before) that you have the wrong power transformer in amp # 2. You should probably remove the power transformer from that amp and get the correct power transformer from Kevin at Dynakitparts.