There are coarse (up to 4 octaves) and fine (to just under a semitone) tuning parameters. A "poly mod" parameter allows the audio output of one voice to feed another's voltage-controlled filter (VCF) when they are layered in "double" mode. This results in a sound with 4-voice polyphony with no audio from the second voice's oscillators, processed through two filters in series. The single low-frequency oscillator (LFO) is free-running (i.e. doesn't restart when a key is depressed), with programmable rate (0.25 to 20 Hz according to the manual), and has programmable depth and waveform (triangle or square). This can modulate any combination of filter cutoff frequency, pitch, or oscillator pulse-width. There is a chorus with fixed rate and frequency. Filter cutoff frequency, resonance (to self-oscillation), keyboard tracking (off, half or full) and envelope amount can be programmed, but the envelope cannot be inverted. The two ADSR envelopes modulate the VCA and the 24 dB/octave VCF. The rate for the polyphonic portamento is programmable. "Unison" (monophonic mode) can be programmed for each patch. In this mode, the envelopes are re-triggered only after all keys are released ("legato", with low-note priority), and a delay of four oscillators relative to the other four can be programmed (fixed at 20, 40 or 80 milliseconds). A program can be "linked" to another so that both are called up and assigned correctly in a split or layer. There is also a programmable output level for each patch to help balance loud and soft sounds. Performance Controls There are separate volume knobs for channels A and B (i.e. the two patches in a split or layer). The footswitch can be programmed to momentarily change patches, or change one of several patch parameters: filter cutoff frequency, ADSR envelope amount or attack; VCA decay or release; voice volume (the momentary value of any of the preceding being user-defined); chorus on/off, or portamento on/off. The parameter value knob can be used to alter one parameter in real-time, although the value will "jump" to the knob's current setting as soon as it is moved and some parameters stairstep badly when treated this way. The pitch-bend wheel is not spring-loaded and is centre-detented. Oscillator tuning can be initiated from the front panel, with this process taking about twenty seconds. During tuning, the instrument is silenced. MIDI Implementation The Split-8 has quite advanced MIDI implementation for an instrument of this vintage. OMNI mode,