Future Retro XS - Manual (Page 59)

TIPS AND TRICKS
SUB OSCILLATOR SYNC
When you are syncing Oscillator B’s frequency to Oscillator A, listen to the effect this has on the
different Sub Oscillator waveforms provided in the WAVE C section. The results can be quite pleasing
with their pitches stepping in unusual ways.
SUB OSCILLATOR SELF MODULATION
The Sub Oscillator waveforms provided in the WAVE C section are derived by dividing the pitch that
Oscillator B is generating. One of the internal modulation sources for Oscillator B is WAVE C, and we
can use WAVE C’s control to select one of the sub oscillators to then self modulate Oscillator B’s pitch.
What this creates is what I will call a pseudo-duophonic serial tone, where we are generating what
appears to the ear to be two different pitches from a single oscillator at one time. In truth, what is
happening is when the sub oscillator waveform is in the low state of its square wave,
Oscillator B’s pitch remains at its unmodulated pitch, and when the sub oscillator is in the high state of
its square wave you get a second modulated pitch. Depending on which sub oscillator division you
choose to use as the modulation source, you can cause Oscillator B’s frequency to alternate between
these two pitches in single periodic cycles, two periodic cycles, or four periodic cycles. You can then
use the B AMOUNT control in the Oscillator Modulation section to set the desired ratio of the two
pitches being produced. You will find that only small amounts of modulation are needed to create
realistic duotones with a single oscillator.
OVERDRIVING THE FILTER WITH TWO OSCILLATORS
In previous sections of the manual we explain that when the input of the filter is overdriven the filter
produces less resonance. However something that might not be so obvious is, let’s say, when we
overdrive the filter with square waves from both Oscillator A and B at the same time. When these
waveforms are in phase less or no resonance may be produced by the filter, but as the waveforms
become out of phase their amplitudes cancel each other out producing a lower level which then does
allow the filter to become resonant during these periods. Try detuning the oscillators slightly from one
another to hear the results.
USING THE OVERDRIVE
The Overdrive section of the XS adds so many harmonics to a sound that you may find it is most
pleasing when using only a single oscillator. If you wish for the sound to be more complex try
modulating the single oscillator you are listening to, or if using Oscillator B try syncing its frequency to
Oscillator A.
SUMMING SIGNALS AT THE FILTER OUTPUT
Although it is a general rule that you never want to connect two outputs of a device directly together, the
XS does make an exception to this rule. This exception is that you can connect the output of an oscillator
directly to the output of the filter, which will then sum the oscillator signal with the signal coming from
the filter. This is possible due to the circuit protection we provide in the XS at the output of the filter
section. Let’s say you want to route the sine wave of Oscillator B directly into the Amplifier section, but
you also want to route white noise through the band pass filter to shape the tone of this noise before it
goes to the amplifier. Simply connect the sine wave signal on the WAVE B jack to the FILTER OUT
jack. You can then balance the ratio of these two signals by adjusting the white noise feeding the input
of the filter.
Remember that if instead, we were to route the WAVE B jack to the AMP IN jack, signal coming from
the filter output would no longer be routed to the amplifier’s input, which would then only allow us to
hear WAVE B through the amplifier.
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