[sdiy] Echolette Echo 400 / Dynacord EC-504:: Anyone have a varispeed mod figured out?

[Kenny Balys]

I am thinking about adding a varispeed control on my Echolette 400 tape delay.

The partial schematics are available here: (look for Dynacord EC-504, its the 
same as Echo 400)
http://peel.dk/Dynacord/index.html

The details of the motor control seem to be missing.

Has anyone done this?

If so, I would love to hear how you did it.