Series One 50 preamp tubes position

[gontur]

I'm looking for a whole tube upgrade but can't figure out preamp tubes position.
Is this layout correct?
v3 v4 v1 v2 ... being v1 the 12AU7 slot?

I wrote some emails to Tube Amp Doctor and they suggest 7025W in V1-V2, 12AU7 in V3, and a 12AX7 in V4

[thephantum]

If you pull the chassis out, the positions should be stamped on the PCB.

[Mogmog]

V3 V4 V1 V2 Trafo

V3 for clean chanels ECC83
V4 for crunch and super crunch chanels - ECC83
V1 ECC82 (All chanels)
V2 Phase Inverter ECC83 (All chanels). The Most important Tube in the Previo.

The ECC82 can't be changed to any other position. It doesn't work properly. The amp lose a lot of volumen.

Same configuration in S1 45 Combo.

Without V3, no sound in clean chanels.
Without V4, no sound in Crunch chanels.
Without V1, volumen drop.
Without V2, no sound.

[aqa]

Tung sol´s sounds good in Blackstar´s series one