Uploaded October 2020 | Updated September 2026, 2 weeks ago
In 1984, Fender put out a synthesizer – the Chroma Polaris.
This short film explains why and how that happened.
With thanks:
Paul DeRocco (original designer and ARP and CBS employee)
Mary Lock (original ARP and CBS employee)
The Alan R Pearlman Foundation alanrpearlmanfoundation.org
Richard @ retrosynthads.blogspot.com
Marc Brassé brassee.com
Midera: youtu.be/fFIsgiG_wX0
rhodeschroma.com
muzines.co.uk
Nathan @ synthchaser.com
…and the owner of the featured Polaris II.
Social:
Facebook.com/AlexBallMusic
Instagram.com/alexballmusic
Nerdy details (from left to right)
Sequencer:
Play, record, stop buttons, although a tempo tap footswitch is also required to operate it.
The polyphonic sequencer can store up to 12 sequences and a total of 650 notes, although the sequencer memory is shared with the patch memory.
Keyboard:
Stack, unison and split modes, plus range selection.
Oscillators:
6 voice polyphony with CEM3374 dual VCOs.
Each oscillator has "saws" (as described in the video) and a pulse wave with manual width and bi-polar width modulation of both shapes. In fact, there's no mixer section and so to lose an oscillator you set a pulse's duty cycle to 0% so that you can't hear it.
VCO 1 has a ring modulator and VCO 2 can be phase synched to oscillator one.
There is a discrete transpose button for each oscillator. You select it and then press a key on the keyboard to do this.
Sweep:
LFO with sine or square waves with a continuous rate. There's one per voice and the sine waves are always free running and different for each voice allowing for LFO modulation with different phase.
Filter:
4-pole CEM3372 with cutoff, resonance, bi-polar sweep depth, bi-polar envelope depth and bi-polar keyboard tracking depth.
Noise on/off is also found in the filter section.
Filter Envelope:
Attack, decay, sustain, sustain decay and release. Touch sensitivity on/off.
Volume (Amp) Envelope:
Attack, decay and release. Touch sensitivity on/off.
Assignable Control:
Modulation section that is uni-polar on the left and bi-polar on the right.
As well as five external pedal or switch parameters, there's (monophonic) glide, volume, mod lever and bend lever ranges, vibrato delay, VCO 1 and 2 vibrato amounts, envelope modulation of oscillator 2 and detune.
Bank select / Program select:
Here you'll find 132 memory slots (A - K and 1 - 12), advanced sequencer commands, external sync settings, midi channel setting and cassette backup utilities.
Midi:
In + Out / Thru
Good midi implementation with control of parameters via CC, although some weren't available at the time of the mkI (e.g. program bank selections and NRPNs).
Chroma Interface:
Parallel port for a proprietary system.
Connectivity:
Headphone out
Audio out low / high
Sync in / out
Pedal in
Sus footswitch in (this also allows you to freeze a note and then use the bend lever to create pedal steel-like effects)
Cassette din
Metronome footswitch in
Processor:
16-bit CPU Intel 80186.
Release:
1984
In 1984, Fender put out a synthesizer – the Chroma Polaris.
This short film explains why and how that happened.
With thanks:
Paul DeRocco (original designer and ARP and CBS employee)
Mary Lock (original ARP and CBS employee)
The Alan R Pearlman Foundation alanrpearlmanfoundation.org
Richard @ retrosynthads.blogspot.com
Marc Brassé brassee.com
Midera: youtu.be/fFIsgiG_wX0
rhodeschroma.com
muzines.co.uk
Nathan @ synthchaser.com
…and the owner of the featured Polaris II.
Social:
Facebook.com/AlexBallMusic
Instagram.com/alexballmusic
Nerdy details (from left to right)
Sequencer:
Play, record, stop buttons, although a tempo tap footswitch is also required to operate it.
The polyphonic sequencer can store up to 12 sequences and a total of 650 notes, although the sequencer memory is shared with the patch memory.
Keyboard:
Stack, unison and split modes, plus range selection.
Oscillators:
6 voice polyphony with CEM3374 dual VCOs.
Each oscillator has "saws" (as described in the video) and a pulse wave with manual width and bi-polar width modulation of both shapes. In fact, there's no mixer section and so to lose an oscillator you set a pulse's duty cycle to 0% so that you can't hear it.
VCO 1 has a ring modulator and VCO 2 can be phase synched to oscillator one.
There is a discrete transpose button for each oscillator. You select it and then press a key on the keyboard to do this.
Sweep:
LFO with sine or square waves with a continuous rate. There's one per voice and the sine waves are always free running and different for each voice allowing for LFO modulation with different phase.
Filter:
4-pole CEM3372 with cutoff, resonance, bi-polar sweep depth, bi-polar envelope depth and bi-polar keyboard tracking depth.
Noise on/off is also found in the filter section.
Filter Envelope:
Attack, decay, sustain, sustain decay and release. Touch sensitivity on/off.
Volume (Amp) Envelope:
Attack, decay and release. Touch sensitivity on/off.
Assignable Control:
Modulation section that is uni-polar on the left and bi-polar on the right.
As well as five external pedal or switch parameters, there's (monophonic) glide, volume, mod lever and bend lever ranges, vibrato delay, VCO 1 and 2 vibrato amounts, envelope modulation of oscillator 2 and detune.
Bank select / Program select:
Here you'll find 132 memory slots (A - K and 1 - 12), advanced sequencer commands, external sync settings, midi channel setting and cassette backup utilities.
Midi:
In + Out / Thru
Good midi implementation with control of parameters via CC, although some weren't available at the time of the mkI (e.g. program bank selections and NRPNs).
Chroma Interface:
Parallel port for a proprietary system.
Connectivity:
Headphone out
Audio out low / high
Sync in / out
Pedal in
Sus footswitch in (this also allows you to freeze a note and then use the bend lever to create pedal steel-like effects)
Cassette din
Metronome footswitch in
Processor:
16-bit CPU Intel 80186.
Release:
1984
