well I got it working, it needs "B+" on the primary center tap to power the output stage, I don't have the docs for the transformer
wiring but the unit also uses +/- 20volts very strange design! there is also a 37 volt supply in the case from these but it seems to
me it was hooked up to one of the plus/minus rails all! very weird stuff all the other EMI use straight +/- 20.