SE amp with 6550 tube

[MWJB]

125ESE is rated at 80mA, not 70mA.

[Alf]

But not good enough for a 6550 if it draws 100 mA ?

Alf

[MWJB]

Why would you need to draw 100mA (360vdc on the plate)? You're going to want >400vdc-ish on the plate, 6550 is a 40W tube, biased at 75-90% = 90mA max. There are SE 6550 guitar amps out there that run less plate current than 70mA and still sound great...I'd see how it sounds from 60-80mA, and a couple of points in between.