On Oct 9, 4:08 pm, "Richard Crowley" wrote:

Is it a big "heavy iron" transformer with the primary connected
to the mains power cord? Or is it a smaller, lighter ferrite-core
transformer driven from a power transistor (or two) Or perhaps
a combination of those, i.e. a switching power supply?

It's a big transformer, with the primary connected directly to the
mains power cord via the on/off power switch.

The service manual I am using is for this exact model. According to
the service manual, there were NO revisions at all in the power supply
(I double checked). The schematic and diagram apply to ALL Nakamichi
CR-7 cassette decks.