KT88 in Ultralinear mode -3db 22hz to 45khz. -6db 15hz to 67khz.
Maximum power 16 watts. Hum 1.2mv. S/N 102db hum removed.

The signal to noise is very dependent upon driver valve choice. The best result was from a NOS Sylvania Angle plate 6sn7. A Chinese no name 6sn7 returned similar S/N but frequency was down -3db at 13khz.
One of my favorite valves, a Sylvania 6SL7WGT was quite noisy with a S/N of 67db, go figure.

EL34 triode mode -3db 15hz to 41khz and -6db 11.5hz to 62khz.
EL34 UL mode -3db 23hz to 52khz and -6db 16hz to 76khz.

The installed valves were Valve Art 5AR4, Sylvania 6SN7 angle plate and new Valve art outputs.

I've been working on a (shock horror) push-pull amp. The transformers I have wound using the same technique I developed for the SE iron. They test very impressive out of circuit. -3db 7hz to 58khz. In circuit they should perform similar as the bias current is self cancelled. The top end may go a bit higher due to the ul taps.

The attenuator xformers are coming along as well. I'm happy with the test results and will now work with taps. I plan to have only 12 taps with a +3db boost tap to add a bit of gain to a passive pre.
Cheers. Earle.