VM2500 Blank Panel Module 1001 VM2500 Dual Envelope Generator Module 1003 VM2500 Oscillator Module 1004-P VM2500 Oscillator Module 1004-R VM2500 Oscillator Module 1004-T VM2500 Modamp Module 1005 VM2500 Filtamp Module 1006 VM2500 Dual Noise/Random Voltage Generator Module 1016 VM2500 Oscilloscope Module 1019 VM2500 Dual Oscillator Module 1023 VM2500 Dual Reverberator Module 1025 VM2500 Preset Voltage Module 1026 VM2500 Clocked Sequential Control Module 1027 VM2500 Dual Envelope Generator Module 1033 VM2500 Sample & Hold Module 1036 VM2500 Triple VCA Module 1042 VM2500 Synthesizer Voice Module 1045 VM2500 Quad Envelope Generator Module 1046 VM2500 Multimode Filter Resonator Module 1047 VM2500 Mix-Sequencer Module 1050 VM2500 Dual Four-Channel Mixer Module 1051 VM901 Voltage Controlled Oscillator VM902 Amplifier VM903 Random Signal Generator VM905 Reverb VM907A Fixed Filter Bank VM911-A Dual Trigger Delay VM912 Envelope Follower VM921 Voltage Controlled Oscillator VM923 Filters/Noise VM927 Multiple VM958 Keyboard/VCO Interface VM960 Sequencer VM962 Sequential Switch VM984 Four-Channel Matrix Mixer VM995 Attenuators VM914 Fixed Filter Bank VM928 Sample Hold VM1630 Frequency Shifter VM901ABBB Voltage Controlled Oscillator VM904A/B/C Filters VM911 Envelope Generator VM921ABBB Oscillator Bank VM Rackmode 10 Band Graphic EQ VM Rackmode 12 Stage Phaser VM Rackmode 3 Band Parametric EQ VM Rackmode Poly Vocal Source Oscillator VM Rackmode Ring Modulator VM Rackmode String Filter VM Rackmode Vocal Source Oscillator VM Rackmode Frequency Shifter VM Rackmode 16 Channel Vocoder VM Miniverse A-440 VM Miniverse Contour VM Miniverse Filter VM Miniverse Glide VM Miniverse Mixer VM Miniverse Noise VM Miniverse Oscillator VM Miniverse Poly Contour VM Miniverse Poly Filter VM Miniverse Poly Glide VM Miniverse Poly Mixer VM Miniverse Poly Oscillator VM Miniverse Poly VCA VM Miniverse VCA

The 1004-R is one of three primary oscillator modules. It's functionally identical to the 1004-T oscillator, minus 1004-T's ability to invert waveforms. We included it for completeness, its cool-looking rocker switches, and for that one weirdo who will swear that the 1004-R is the best-sounding 2500 oscillator. It can be used in the audio range, or as low-frequency modulation sources.

Inputs, Outputs, and Controls

1V/Oct jack- Accepts a CV input for pitch. Typically this would come from the Pitch jack in the IO Panel CV Out section, or from a sequencer CV out.

Frequency / Coarse and Fine- The Coarse control sets the base frequency over a nine-octave range, in octave increments. The Fine control allows continuous fine pitch control and is configured as a "multiplier" with center position being nominal and a range of 1/2 pitch to the left or double the pitch to the right (i.e. +/- one octave).

Enable- Turns the oscillator on and off.

Range- Generally this will be set to Low when using as a mod source, or high for audio-range signals.

Pulse Width (PW)- This sets the width or "duty-cycle" of the pulse wave (the very bottom waveform on the panel). It has no effect on any other waveform. Its default setting of 50% outputs a perfect square wave, rich in odd-order harmonics. Moving the knob left or right narrows its width as well as the thickness of sound until it almost disappears at its extremes.

PWM mod input jack and attenuator and PWM - You may have noticed that moving the Pulse Width knob back and forth creates a nifty sound; instead of wearing our your mouse hand, the PWM Mod input can be used in conjunction with an LFO, envelope generator, or other mod source to continuously vary the pulse width. The attenuator knob is bipolar; it allows positive (clockwise) or inverted voltage control (counterclockwise). It defaults to center zero position.

Frequency Mod 1 and 2 input jack and attenuator- This is used for externally modulating the oscillator frequency. It's useful for adding vibrato with an LFO, siren noises, envelope-controlled pitch sweeps, etc. The attenuator knob is bipolar; it allows positive (turn right) or inverted voltage control (turn left). It defaults to center zero position.

All mod inputs are exponential, that is, for a given mod input voltage, the mod amount increases as frequency increases. For example, if the base frequency is 1000 Hz, and a bipolar wave is applied to the mod CV input, the frequency falls to 500 Hz and rises to 2000 Hz. Because audio frequencies are inherently exponential in nature, the resulting frequency rises and falls exactly one octave.

Waveform rocker switches- Five waveforms are available: ramp, sawtooth, pulse, sine, and triangle waves. Each wave can be turned on and off individually. Waveforms are output to the master Output jack at the bottom right of the panel.

Waveform individual output jacks- These can be used simultaneously, or in any combination. They are unaffected by their corresponding rocker switches.

Master output jack- Mix of all individual waveforms, dependent on wave rocker switch settings.