EL-34's won't bias.

[Tubetec]

Shame really , you help someone out , they come back and try and bite you on the ass for it,
At least the vast majority of our new members here are both courteous ,appreciative and here to learn something .

 

[johnR]

I could understand being concerned with "peak power" if this was a non-master volume amp and distortion and sustain was being generated by cranking the amp. But, it's not and there's almost nowhere you'd use this at "peak power" or cranked, today especially. Even in studio there's no need to crank the master above 4-6.

With the master turned up to 6 on these amps you will quite likely be overdriving the output stage unless you've set all the tone controls pretty low. You can check this on an oscilloscope.

IME it's quite common for guitarists who use Marshall master volume amps to turn them up loud enough to give at least some power amp distortion in a live gig situation; it's part of their sound.