I agree with "two wheelin' Bob" up above. This is something that you should learn to do if you intend to own / operate a tube based system for any length of time. Keeping track of the bias will also let you know what state the tubes are in, as noticeable shifts in bias are also typically related to shifts in tube performance. If you notice that you have to adjust bias every time you check it, it's time to get some new tubes. This is not to say that the ones in use are "bad", only that they are not as stable as they used to be. They could make for great spares "just in case". Sean
>
>