DOD 670 Flanger need voltage readings

[CheapPedalCollector]

I've been repairing a DOD 670 Flanger and I need some voltage readings from a working unit.

I've rebuilt practically the whole thing and got it working but it's very distorted from the BBD which I know is good because it works in another device. I need some voltage readings at the mixer side of the 4558 and the output pins of the SAD512, I would like voltage readings from the NE570/NE571 as well.

A bit of background on it.

Replaced all chips with new/known working ones.
Complete electrolytic cap job and PSU section rebuild.
Resoldered everything as it was full of cold joints.
Measured all resistors with one leg pulled up, all test good.
Checked all signal caps, all test good.
Replaced bias trimmer as original was 30% out of spec (low).
Cleaned and tested pots in known working circuits.
In bypass mode it works fine.

I have only 1.7V on the mixer side of the 4558 which is what I figure the issue is, I'm trying to track down exactly what is still failed. I suspect something in the feedback circuit.

Will post pics on request.

Thanks in advance.