This...
is a split image of the rear panel of the 644.
On the bottom image, above the MIDI-Out connector, is a little squarish connector with 4 pins. That's the P/S input jack. The P/S (PS-M1) power plug would fit it, accordingly.
The top of the connector is nearly square, but with keyed a center detent.
The bottom of the connector has more rounded corners, that's not quite square.
The shape is intended to safeguard that the power input will only ever be plugged in one way, i.e., oriented correctly.
The power itself is not exotic, but is +/-10Vdc (on 2 pins) and Gnd (on 2 pins).
The pinouts and P/S current rating I could read from the manual or off the actual PS-M1 module, but neither is handy at this moment.
It occurred to me that you could hardwire a DIY PS module directly to the squarish PS input jack,... if it really came to that. There might be individual molex pins you could get OTC that would fit, then just solder your +/-10Vdc and Gnd to the pins, and secure it with something like sealing wax, epoxy or tape. Honestly, I'd rather see the proper connector sourced and do it that way, but y'know,... if yer desperate and out of options, there's always the solder gun and tape!
A main point to curious newbies and readers is that if you buy a 644 without it's dedicated power module, you have a real fine doorstop!
I'll check the 644 manual and PS-M1 module in a while on the details current rating, the specifics of the Euro ps module (whether it's usable for US or universal/autoranging), and the Save/Load Scene feature.
I also got a TASCAM MIDIStudio tutorial on cassette with my 644, but I've misplaced it temporarily, as yet TBD.
