Anyone here know the Mark Levinson ML-2?

I've got a stereo pair of them here that both work fine except for excessive DC offset. Is this a known issue?

I've checked / cleaned the gold edge connectors already. Otherwise these seem pristine and low hours. No evidence of prior repairs, no evidence of overheating (believe it or not).

I looked thru the forum but did not find a lot on this model. Thanks for any suggestions that you may have. I'm reading 0.2 & 0.7VDC on the outputs after warmup - way too much.

(these are later models w/toroid xfmr, FWIW)