Architecture

Sunfish can be broadly described as a three-oscillator, two-filter subtractive polysynth, with many odd quirks.

We've modelled interesting circuits from lots of obscure 1970s and 1980s hardware, and then tweaked them further until they worked together to make something fresh.

The Morpher

The central panel houses The Morpher. Clicking or dragging on this area smoothly scrubs between different sounds:

• Pick a category with the buttons underneath the screen.
• Click/drag around the screen to explore sounds within that category. This replaces the current sound.
• Flip the 'bank' switch (bank 1 / bank 2) for more sounds in each category.
• Found something close? Turn the morpher off with the ON button (or just grab any locked control) and the current settings are stored back to your session. Then tweak with the full control set.

The 'vox' sounds are best with the modwheel up about 20%. The morpher position can be host-automated with the morph.x / morph.y parameters.

Oscillators

With finetune at zero, osc1 and osc2 stay phase-locked - so in mono mode, osc2 can work like a suboscillator, and in poly mode you get a lovely stability to chords and pads.

osc3 has a spread mode that adds a detuned copy, and a "ghost" function: a per-voice, pre-filter/VCA, pitched spectral accumulator - a per-note reverb. It adds shimmer to pads ... or explosive meltdowns to bass.

Filters

Filter 1 is a formant "vocal" filter with seven different models ("personas") - some from academia, some based on ideas from hardware like the VP-330, some tuned by ear. Formant mix and vowel can be modulated by sources including MIDI params.

Filter 2 is a subtractive filter with 5 circuits:

All filter circuits except 'clean' can overdrive; when filters are slammed, resonance acts more like an additional waveshaper control.

Filters are fully polyphonic. Individual oscillators can be selected to skip the filters for interesting layering possibilities.

Modulation and Control

• Lots of stuff can be modulated. Most modulators have one toggle to give a bit of freedom without overwhelming with controls.
• There's a big modwheel bay in the middle that routes modwheel signals to different controls. You can set three of those signals to per-note MPE controls with the toggle under the dial and the MIDI config in the top-right of the window. Per-note pitch bend should also work.
• There's an arpeggiator and all the other standard synth features, but everything has been tweaked and nudged to be a bit different from normal. E.g. the envelopes are all velocity sensitive by default (there's a master override) like some mis-built analog gear, osc1/2 and osc3 slide use different controls and algorithms so you can do some cool SID-style tricks, the whole thing has been built to sound great but be just bent enough to stand out.

Effects

• Chorus is a modified version of the ensemble module from our Gossamer plugin, based on classic 1970s string synths and early 80s effects. "In-between" values are crossfaded between different circuits. Higher settings are more modern than lower settings.
• Reverb is based on a late-1990s algorithm, tuned to sound best on big pads.

Advanced Notes

• The filters are all circuit-modelled, and can get very gnarly with loud, detuned content with lots of harmonics. The "clean" filter has no waveshaping; use this if you need maximum clarity.
• The filters add a LOT of character, but they can dominate the sound at some settings. If the oscillator controls don't seem to be doing much, back off on the filters a little.
• The osc3 "ghost" control has a lot of power to add shimmer, density and unpredictable weirdness to sounds. With osc3 on, start with pitch at +12, mess at 0, and turn the main osc3 mix control up about half - you should hear a jumbly octave layer emerge on top of held notes. The extra harmonics can add a lot of unpredictable timbres when hitting an overdriven filter as well, which is an amazing trick for complex slow bass tones.
• The oscillators and filters all use a lot of tricks to efficiently reduce aliasing (weird pitch artifacts), but there are some pathological cases where some artifacts can creep in. Select the 4x quality setting in the settings dialog to minimize this.
• Each oscillator can have a different vca envelope, allowing for interesting layering tricks. Use the per-osc filter bypass controls and the LFOs for additional interesting sound evolution.
• The controls have all been extensively tuned for interesting control options. For example, the first 5% of the vibrato speed dial drops speed by about 10x, for woozy "seasick"-type pitch modulation
• We tried to reproduce some of the weird behaviours we found on some old hardware we studied. The note slide, legato, (velocity-sensitive) envelopes, and keytrack controls all have curious interactions with the surrounding features.

Controls

Labels are as shown on the plugin screen. Hover over any control in the plugin for the same help text.

morpher

Sound morpher. Replaces current plugin sound. Click/drag the screen to explore sounds within the selected preset category (underneath).

oscillators (all)

osc1

Divide-down oscillator, 1977 variant - quirky. Osc1/2 are phase locked if both finetunes are 0. Drag screen to change waveform.

osc2

Divide-down oscillator, 1978 variant - conventional. Osc1/2 are phase locked if both finetunes are 0. Drag screen to change waveform.

osc3

Wavetable oscillator, modelled on devices from 1982-1985. Drag screen to change waveform. 'spread' control adds an additional detuned Osc3. 'ghost' control adds a slow per-voice spectral processor.

vox (formant filter)

Vintage-modelled formant filter bank - up to 8 bandpass filters for vocal and resonator effects. Drag screen to change mix and frequencies.

filter

Subtractive filters, circuit-modelled on a curious 3391-based OTA filter, a crunchy 6581-based chiptune filter, and a tuned tone control. Circuit models have been tweaked to work best with the oscillators but retain their original character. Drag screen to change cutoff and resonance.

env1/env2/env3

ADSR envelope. Analog-style, velocity sensitive. Use 'max velocity' switch in 'engine' section to switch envelopes to full volume. Drag screen to change envelope timings.

vibrato (lfo1)

lfo2 and lfo3

Wavetable LFO. Drag screen to change rate and shape.

modwheel tweaks

effects

engine and arp

global and pitch