1. Is it better to bias tubes after 10 minutes or 1 hour?

candyliquor35m

or does it matter?

2. As tubes get older, will their bias readings tend to go up or down?

madmax

1. There are different reasons for different things. When you first replace tubes or swap them around you need to start bias procedures right away because bias could be very high with a different tube. As they start warming up (10 min) they will be approx where you could set it and feel confident you are safe. After an hour you could set it and say thats good enough and forget about it. After several hours of play you know for sure they are settled in and that would be a good time to adjust.
madmax

2. Down

candyliquor35m

thanks

reeltrouble1

After things have settled out, watch for one that drifts, could be a sign of tube starting to go. You should only have to check things about once a month once you know they are holding steady, some folks go longer, some never bias.............Yikes.

But ain't tubes fun.

RT1