MOTM

At 8:02 PM -0600 2002/04/29, Adam Schabtach wrote:
>What's the difference between AM and RM? I mean, isn't a ring 
>modulator essentially a multiplier of two signals, which means that 
>the instantaneous output is the product of the instantaneous 
> amplitudes of the input, which means amplitude modulation?
>

RM is a four quadrant multiplier, whereas AM is only two quadrant. If 
the control voltage in an AM goes negative, the output signal is 
clamped at zero. If the control voltage in RM goes negative, the 
output signal is the inverse of the input signal (180 degrees out of 
phase).

You can see (hear?) this in operation with the 110. Put a 320 square 
wave into the CV input of the VCA (i.e. the AM half) and your 
favourite 300 waveform into the IN. The output goes on/off/on/off. 
Now try it with the RM half. The output is on/on/on/on with a bit of 
a click as the output waveform is switched between normal and 
inverted.