I do appreciate it much. The EL34's application is bias dependant? Huh.
Yes indeed.
For instance, the bias point of EL34 tubes run in triode compared to Tetrode can be different. The bias point of Mullard EL34 tubes in the Tube Research GT400 (yes, it works-been there-done that) is different than a Dynaco Stereo 70 and different than the Wolcott Presence 220.
And as I said, input tubes for all three of these amps (and input design circuit) are all very different too.
The bias for the Dynaco Stereo 70 is quite low (about 1.56 VDC) compared to more modern amps and perhaps the reason so many EL34 Mullards have survived for 40 years. That and the fact Dynaco produced about 250,000 of these before they were discontinued, means we had a rather large supply to begin with.
Here is a link to different voltages and bias points the EL34 can be set up for. This was for popular guitar amps but the principal is the same.
http://www.diyguitarist.com/Images/BiasChart-EL34.jpg