VTA-ST120 Bias resistor settings,

Hello,
          Well After many hours of building my VTA-ST120 kit. I can say that it is complete. Sounds wonderful and has no hum. I just have one question about biasing the VR's? Believe it or not all four are set dead on 0.50 Ma. The one in question is the right rear Bias resistor. The other three Bias resistors are set in the same position right around 11 o'clock. When I first power the amp up after a few minutes of warm-up I check the Bias setting. And I find every time the left rear Bias is higher than the rest? After I adjust it the vr is at 8 o'clock. Does it matter that it does not line up with the other three Bias settings? I am using a headphone tube preamp until I can afford a real preamp/Thanks,

It doesn't matter at all. Usually I find that that each tube requires a different setting and it's just a coincidence that three of yours are closely matched. Congratulations on a successful build.

I find I have the same issue. My right rear output tube bias always rises with use. The other 3 are always somewhat close to each other and to 0.5v set point but the RR is higher - .510 to .512v. Drives me crazy.

Thanks, guys for your thoughts, David my RR tube like yours is always on the high side also. And a big thanks to Bob for sending me the extra parts and his help with the amp. I have found the Dyanco customer support to be the finest you will ever find anywhere thanks to Bob. Other companies should treat their customers, as well as Bob, does. Now all I need to do is save money to buy a tube preamp instead of using an aiyima tube-b3 headphone preamp. I will be asking if there are any online preamps available in another post.

is it always the RR socket, or does the problem follow the tube?
If the problem follows the tube, replace the tube.
If the problem is the RR socket, resolder all the connections on that socket.
Also check the solder connections on the driver board that lead out from that bias adjustment.