Hi,
I'm glad to see I'm not the only one interested in this project...
So first, here is the deck motor speed circuit:
https://drive.google.com/open?id=0B5VFeUGvnPP0OXJ5RU81V25YMlUYou can find a complete tutorial for it there:
http://casperelectronics.com/motor-speed-mod/I must say it's verified with my point to point build, and really efficient.
Then I'd like to add a modulation to it, something like this:
http://2.bp.blogspot.com/-80ID5jcny8Q/U02DfXetl6I/AAAAAAAAGwQ/yZR6vQxuOdI/s1600/Grind+Customs+FX+DeProfundis+Modulation+Daughterboard+Rev2.pngBut I have to experiment the implementation of this daughterboard...
I think it would be cool to have a chorus/vibe tape echo, right?