Balanced Modulation
2002-05-18 by grantrichter2001
Gary Chang was kind enough to point out that the Wiard contains 3 balanced modulators. This is also called "ring" modulation and produces the sum and difference frequencies while suppressing the original carrier and modulation frequencies. The technique is used in the Music Easel balanced modulator, simply crossfading between waveforms 180 degrees out of phase. Try this experiment using the Envelator: 1. Env1 Out + is normalled to Mix module Mix 1 input. 2. Patch Env1 O- (Out minus) to mix module Mix 2 input 3. Set Env1 to "Cycle" with A and D set short 4. Listen to the Mix module output 5. As you advance the Mix control, the signal will null when the two out of phase versions have equal amplitude and cancel. 6. Now take an audio VCO sine ouput into the MixMod input and advance the MixMod control. You will hear the "Klang" (sum and difference) tones fade up. The same technique should work with the Mixolators using the X+ and X- outputs of one to feed the X and Y inputs of the second. Modulation signal to X1 input of the first with Z at max. Feed the carrier signal to ZMOD of the second, and null the modulation signal with the second Z control. This is essentialy what the Ring switch does on the Mixolator, but this technique is more adjustable with better linearity.