[sdiy] XOR ringmod

[Tim Ressel]

--- Michael Ruberto <frankentron at hotmail.com> wrote:
> Are the XOR gate ring modulator designs a true ring
> mod effect? in other 
> words, if I put in 220Hz and 880Hz will I have
> sidebands at 660Hz and 
> 1100Hz?

No, it is not a true ringmod. In a true ringmod if you
put in signal with harmonics present, the harmonics
also go through the A+B, A-B transformation. And the
original signals are supressed. 

In an XOR 'ringmod', an edge is output every time
either input transitions, so the input signals are
present at the output. But the harmonics on the input
signals are not summed and differenced. However
because the output is square waves, the sum and
difference signals on the output have their harmonics
present.

Hmmm ... Now I have to add an XOR ringmod to my synth.

--tr



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