The Pulse 030-7330-0 that palchiu suggests is exactly what I ended up buying (from Mouser). I had the same professional PCB assembly firm remove the 230V transformers and mount the new Pulse units. But they don't do voltage tests.
Back home, a technically adept friend who owns a good multimeter applied 120V power and tested the transformers. 120V in, exactly right on both. But TR1 produces 6.65V and TR2 = 18.09V. (
) TR1 gets hot, while TR2 remains fairly cool.
This makes no sense to us. Is a transformer defective, or is there a short downstream? Or other???
Putting the probes on various points on the regulators and on the outputs yielded even more puzzling readings. Exactly which points are the test points on regulators and the output?
I should add that I ended up substituting two OPA1641AIDs for the AD8610s on the recommendation of a local headphone and amp expert who likes the OPA better than the 8610. I assume this will not alter the essential functioning of the amplifier?