[morzh]

What I don't quite get is this:

1. 0.7A at 65V, does it happen with both channels or just one connected? Does not even matter which one? Are you sure.
2. You still know for a fact all your transistors are good?
3. If your Q10 Vbe is almost zero and Q12 Vbe is 34V and your B+ is 65V something should be really smoking. That something would be your R32/R34.

Now, IF both your E2 and E4 are grounded like they should be and B+ is connected, here is your DC path for Q4:
R14 - R20 - D2 - VR4- Q4 C to E - R22. This sets up the DC output.
Now the feedback tht sets it is
R16-VR2-R18.

If you were to remove the output transistors (totally, disconnecting all wires) the VR2 will bring the output (C14plus) to the midpoint of your B+. And the Vc of Q4 should be close to it, maybe a volt or so lower.
If after that you add your power transistors and it gets screwed again, either they are bad or 1/2 Ohm resistors are. Or your C6 or C8 is leaky.