Re: Maybe I am just being unbiased...


"Elvis Kabong" <ampscience@xxxxxxxxxxxx> wrote
....

There are several methods to use in biasing.
There's the scope method as you mentioned.
There's the bias probe method or soldering in 1 ohm 1%
tolerance resistors between output tubes' cathodes and
ground which is basically the same thing as using the bias
probe.
Then there's the "darkroom method" of biasing the tubes in
the dark so you can see when the plates start glowing, then
back down the bias control so they don't. However, there
is one exception to using that particular method and that is
with JJ power tubes. Their plates will simply not glow even
when they are underbiased.
One more method is the transformer shunt and that is measuring
current between the plates and the power transformer's center tap
to chassis ground.

One day I tried all 4 methods and took readings of the amount
of negative voltage at the grids of the power tubes after using
each method. They were all within 1-2 volts.

*Watts*, Ed... how many watts difference? Sounds like
quite a bit. You were going great up 'til then.
__
Steve
..


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