A guide to building the Pass F4 amplifier

I "accidentally" have SIX F4 boards but parts for 1 amp, and enough jfet pairs for another but I was thinking, if i want to use it with the F4 outputs missing to buffer output for a M2 OPS ?
I'm using a DHT 14x preamp I'm building for it thus I have the gain, it's just a tad weak, I thought of B1 but I don't have good matching 2SK170 pairs and that's a extra power rail while I can use the power rail for the M2 OPS