During the initial start up I noticed that the AC filament current was very low (~200 mV) and the 12AU7s were not glowing (but they did get a bit warm). I used the 12AT7s that I have and they did glow? I went ahead and put in the rectifier and the left power tubes and attempted to bias. I noticed significant hum coming from the power transformer, which settled down after the rectifier had been on a few moments. The hum was still audible after a minute. With both bias pots in the center position the bias voltage for both tubes was very high. Turning both pots completely clockwise only reduced the voltage to ~0.8 volts. On the right side things were a little weirder. I started with both pots full clockwise, turned on the amp and the readings were ~0.3 volts for the front tube and ~0.09 volts for the rear tube. What was weird, was when I attempted to increase the bias voltage on the front tube (the pot at full clockwise) the voltage would go down, and when adjusting the bias on the rear tube (the pot in the full clockwise position) the voltage would go up, but only slightly over one volt, and so would the hum coming from the power transformer? Adjusting the rear bias seemed to draw much more current for some reason. I do need to check the tubes I was using, too.
Another strange thing, the resistors in R7 and R8 are 6.8K, but when I measured them in the board they read 100 ohm? I pulled one out and sure enough they were 6.8K.
Anyone have some insight on this?