"Phil Allison" wrote in message
...

"Arfa Daily"

He wants the output bias changing from fixed grid to cathode auto,


** That will either lose you a lot of output power or cook that puny power
tranny ( by going close to class A operation) if you don't do it the
smart way.

Not recommended either.




..... Phil





Well, that one is a well known and documented mod for that amp, so I'm not
too concerned about doing it. However, I take (and somewhat agree with) your
point. Personally, I would prefer to make the fixed grid bias variable
within 'blues to rock' limits, and give him another knob to twiddle with,
but he is adamant that he wants that particular cathode bias mod. I did
offer to make that switchable for him, but he just wants it changing and
leaving at that. You can only advise these people, but in the end, it's his
amp, and if he's prepared to pay the money to have it done at his own risk,
then that's fine by me ...

Arfa