Oberheim Xpander

Picture


























MODULATION SOURCES

5 LFOs
5 envelopes
3 tracking generator
4 ramp generators
Lag processor
2 pedal inputs
MIDI velocity
MIDI release velocity
MIDI pressure
2 MIDI levers

MODULATION DESTINATIONS

Oscillator 1 frequency, PWM
Oscillator 2 Frequency, PWM
15 VCAs
VCF frequency, resonance
FM gain
Envelope parameters
LFO: Frequency, amount

FILTER MODES

1/2/3/4-pole low-pass
1/2/3-pole high-pass
2- and 4-pole band-pass
2-pole notch
3-pole phase shifter
3-pole phase + 1-pole low-pass
3-pole high-pass + 1-pole low-pass
3-pole notch + 1-pole low-pass
2-pole high-pass + 1-pole low-pass

THE VOICE

2 VCO
1 VCF (15 modes)
15 VCAs (some in software
1 FM generator
1 lag processor
5 digital envelopes
5 digital LFOs
4 ramp generators
1 noise generator


Xpander programming discoveries


  • RAMPs sound like they have faster attacks than ENVs. (Or is this my imagination?)

  • You can obtain in-phase frequency multiples of of a LFO signal (triangle wave) by routing it thru a TRK set to [0, 31, 63, 31, 0] (this doubles the frequency). [0, 63, 0, 63, 0] gives a crude quadruple-frequency wave. This process can be repeated with more TRKs in series of course.. (if it weren't for the fact that the whole matrix mod scheme implemented in software, there could be some interesting FM effects to be had there!)

  • The TRKs can also be used to create weird LFO wave forms. Or to skew the distribution of LFO noise, or LFO sample-hold-noise. Or to create weird envelopes for that matter, by routing a RAMP into one.

  • Another good use of the TRKs are to assign a bipolar lever (or anything else) to more than one parameter: two TRKs with values such as [0, 15, 31, 31, 31] and [31, 31, 31, 47, 63] split up the lever into one only-negative and one only-positive signal.

  • The LAG unit can be used for sample-and-hold. Set to EXPO, RATE=63. Modulate the rate with the "GATE": GATE=63 => sample, GATE=0 =>hold.

  • Also a LFO can be used to S/H with a bit more hassle if the LAG gen is used for something else; here's an example that enables you to sample a signal with PED2 (63=SAMPLE, 0=HOLD). LFO1 OUT has the sampled signal.