JTM45 build vs OT impedance and PT voltage

[Jana]

If it was me, I would pick a PT that gives about 370V B+ such as the Marstran 1202-164 or the 1202-118. I would also use the 784-139 OT. That OT has a normal primary impedance of 3K5 into 4, 8 or 16 ohms which means that it is 7K into 8, 16, or 32 ohms.

Why go this route?

You can run EL 34 or 6V6 tubes. If you pick your tubes before hand, you can even find EL 34s and 6V6s that will swap without a rebias. I do it on my latest Marshall build.

Maybe think about swapping the PT on your 2204 for a lower voltage transformer and run 6v6s in it with the option of using EL34s if you need more power.

[Badside]

try the classictone PT with dual taps for high and low voltage. and use a standard 103 8k OT. this way you can use 6v6s and lower voltage or kt66s and higher voltage (I prefer the latter)

Ohhhh, Classictone 40-18054, 625 and 690 taps! Hadn't seen that one.
They say around 379V with a 5AR4 recto on the low-tap, then I can just switch to the high tap if I want the "true" JTM45 tone, or go between tube and diode recto (for around 420V)

With the 18-039 OT (8K) and 18058 3H choke.

We have winner!

[Roe]

try the classictone PT with dual taps for high and low voltage. and use a standard 103 8k OT. this way you can use 6v6s and lower voltage or kt66s and higher voltage (I prefer the latter)

Ohhhh, Classictone 40-18054, 625 and 690 taps! Hadn't seen that one.
They say around 379V with a 5AR4 recto on the low-tap, then I can just switch to the high tap if I want the "true" JTM45 tone, or go between tube and diode recto (for around 420V)

With the 18-039 OT (8K) and 18058 3H choke.

We have winner!

yes, that's a good solution