MS20 ring mod

[Xyplex2 at aol.com]

I would like to experiment with the MS20 ring mod.
I know that it uses a 4011 nand and it only takes square waves.  I also know
that it does not take - voltage.  I want to build a simple 555 LFO and mix it
with my voice.  Can I use a diode to kill all the - voltage and send it into
the nand gate?

The unique distortion could be interesting.  I also was wondering if someone
could send me a text file of the schematic for the ring mod.  I am having
trouble getting access to a fax machine.

pete