[sdiy] (diy) MS 20 Ringmod

[Don Tillman]

   Date: Wed, 22 Aug 2001 11:18:28 +1000
   From: Paul Perry <pfperry at melbpc.org.au>

   At 11:37 AM 21/08/01 -0700, Don Tillman  wrote:
   >Sure, the difference is audible when you mix the
   >ring modulated signal back in with other signals.

   ????? the output of a ring modulator doesn't contain the input
   signals, so I cant see how you could tell the phase, even by
   mixing.  

Ohhhh, in the typical case, yeah, that's true.  

If there were other modulated signals in the mix you could tell.  

And if you apply DC to one of the inputs and use the ring modulator as
a voltage controlled inverter, it's pretty easy to tell that the
signal is inverted in the mix.

But now that I think about it some more... I suppose that an inverted
XOR gate is closer to the intent of a ring modulator than a regular
XOR gare.  By that I mean, if we have two inputs that can be either
+1.0 volt or -1.0 volt, and the +1.0 volt translates to a logic 1 and
the -1.0 volt translates to a logic zero, then an inverted XOR gate
matches a multiply operation.

  -- Don

-- 
Don Tillman
Palo Alto, California, USA
don at till.com
http://www.till.com