Peavey 5150 Combo Preamp Tube Function

[JD]

I finally found a good set of prints for the 5150 combo from Peavey. Everywhere I read on the net states V5 (closest to the power tubes) is the preamp PI tube. The schematics seem to clearly identify V4 as the PI if I'm reading this correctly. From what I see the preamp breaks down as:
V1 - Input Gain
V2A - Reverb send?
V2B - Gain?
V3A - Effects loop send & return?
V3B - Gain/cathode follower?
V4 - PI
V5A - Tone stack recovery (cathode follower?)
V5B - Reverb recovery

Can anyone shed some light on this?