hey tom. from what i can gather, the 2sa1370 and the 2sa1015y. in one channel the voltage between them is 100v and 3.25 to ech side of 1370 going to 1015y. on the other channel, it only has .5 volt on each side. i would think that this is the reason i can't adjust the bias in one channel. one side stays around 4.5mv, while the other is around .23 volts(i may be off as my memory is not so good on this right now). anyway, i appreciate any help. thanks again.