The mixer was a fairly obvious addition because by now we had ring modulator out, x through, y through and two sub bass outputs which all needed to be mixed together. I’ve always loved the simplicity of the discrete transistor CP3 mixer, and even though it clips quite severely when overdriven its distortion really compliments the predominantly softer sines and triangle that are usually associated with a Ring Modulator. The Z input has a different phase relationship with the core than Y input, so although it is effectively a second modulator input it can add some interesting effects that can’t be achieved just by mixing two signals into the Y input. When all of this is put together it becomes a rather unique module that really is greater than the sum of its parts.
The Sonic XV is a filter that goes beyond
filtering with wave shaping both of the input and
resonance circuits. The name is a give away
but what is the filter based on and where did
the addition of wave shaping come from?
I really wanted to create a module with an “East
meets West” approach, the East coast Moogs and
Arps followed the more traditional method of
generating harmonically rich Sawtooth and Square
waveforms and then subtractively filtering them.
Whereas the West coast approach of Buchla and
Serge was to start with triangle waves and then
wavefold, or apply FM, to them under voltage
control to create more harmonically rich sounds.
The idea with the Sonic XV was to combine both subtractive filtering and wavefolding into a single module and this approach means that it is now possible to wavefold first and then subtractively filter afterwards.