simple website templates

Fender Rhodes
Chroma Polaris

Analog polysynth (1984)

fender rhodes

"Son of the legendary Arp Rhodes Chroma synthesizer, the Polaris is a kind of second version a little simpler but still powerful version.  The machine was originally designed by ARP engineers, but then ARP society was bought by Rhodes 2 years before the commercial release."


KEYBOARD 61 keys with basic velocity system., quite sturdy and heavy about 19kg!  Main panel features 23 sliders and 62 buttons for edit process; central slider is assignable to one of the 14 available parameters while on the right side there are 2 levers for modulation and pitch bender. NOTE: POLARIS II Should be same machine at 100% with different outfit for Japanese market

MEMORY  132 sounds RAM +  12 RAM sequencers. 
Data backup can be done by MIDI SYSEX or tape storage - several hardware modifications expands the storage capacity.

Terminal connectors:
1- mono audio out (high / low impedances)  
2- headphones out 
3- tape interface 
4- Midi interface 
5- sync IN or OUT for sequencer synch 
6- custom chroma interface connector (for APPLE II computers) 
7- pedalswitch inputs (x2)
8- pedal input

Chroma polaris


SOUND machine core is a 8-bits CPU Intel 80186 manages 6 voices polyphony and a voice is composed by 2 oscillators VCO (OSC1 + OSC2) which structure is based on CEM 3374 + a white noise circuit + a sub-oscillator. 
System manages different voice allocation modes:
- up to 3 voices assignable to different Midi channels
- 2 sounds can be stacked in UPPER and LOWER part.

oscillatorsPolaris Oscillator 1Polaris Oscillator 2
SHAPESsawtooth / squaresawtooth / square
pulse width YESYES
volume bal NONO
ringmodyes (fixed depth)yes (fixed depth)

Envelope, filter and LFO

- EG1  VCA: 3 stages ADR 
- EG2 AUX: 4 stages ADR + 1 extra time.

FILTER  resonant 4-poles lowpass filter based on Curtis CEM 3372 with cutoff and 8 fixed resonance levels.
 Keyboard tracking attenuates filter effect over octaves (to both low or high part).

LFO a single delayed low oscillator (range 0,1 to 10Hz square and sinewave) modulates:
- DCO1 & 2 pitch 
- PWM pulse 
- VCA amplitude 
- VCF filter (the "SWEEP").


Sequencer & Maintenance

SEQUENCER  single track polyphonic, about 700 notes that can be recording in either real-time or stepmode. Of course Polaris can be also played byt MIDI with a great full Midi implementation: in fact all sliders sends the relative control changes.

REPAIR and MAINTENANCE some common issues:
- keyboard velocity system may need also to be periodically calibrated. 
- power supply drains too much and it has been reported various issues of faulty power supplies.
- buttons membranes is infamous for being highly unreliable and needs cleans or technical cares or remplacement by third part (pic below with my old mate Alessandro Petrini)

Chroma Polaris Technical Data

Type: analog polysynth
Country: USA 
Keyboard - 61 keys w/ velocity 
Polyphony - 6 voices 
Oscillators - 2 VCO's: sawtooth / pw 
LFO: 1 modulator Sine or square 
Envelope: 2 EGS 
Sequencer: 700 notes 1 polyphony track
Sync: analog / midi
Midi interface: yes (primitive)
Memory - 132 patches 

Price: 1500-2000€ up

CPU:Intel 80186 
Weight: 19 kg 
Dimensions: n/a 

video demo

Do you use this machine ? do you like it?  Let us know in the comment field just below 


Share this page


Fender Rhodes Chroma Polaris Fender Rhodes Chroma Polaris
85 out of 100 based on 1 user ratings
1500 to 2000 from 1 sellers Sellers: