RSF KOBOL keyboard (1978)

The legendary French monophonic synthesizer made by the great Fernandez team Ruben and Serge Fernandez.

 

KEYBOARD (weight:10 kg) 44 keys.
This main panel features 28 knobs, 5 switches and 15 buttons. On the leftmost part there there are 2 wheels for modulation and pitch control.

Front panel terminal connectors:
- audio out at high / low impedance
- control voltage for VCO
- control voltage for VCF
- gate control
- external audio process line input
- clock trigger input

VOICE monophonic machine based on subtractive synthesis.
A voices is composed by 2 syncable oscillators with individual settings:
- 4 octaves height
- volume
- tuning

 

OSCILLATORS voice board generates 7 main waveforms with intermediate shapes:
- triangle
- saw
- saw 2X
- various % rectangle pulses
TECH: the waveform transition is smooth and very harmonics.

FILTER the VCF is a 4 poles resonant (up to auto-oscillation) filter based on SSM-2040 chip.
A keyscale function on filter can be engaged.

ENVELOPE 2 EG generators each with a 2- stages ADS:
- EG1 VCF
- EG2 VCA
Special bypass switch activates the VCA drone mode.

LFO a single oscillator (tri / sqr) modulates 2 destinations:
1- VCO pitch
2- VCF cutoff

PERFORMANCE some handy functions for:
- glide legato mode switch
- decay on/off
- keyboard octave selector
- cutoff knob

CV some stages can be controlled by external tensions (1V/oct) such as:
- VCF filter cutoff
- VCO pitch with GATE

SEQUENCER a 2X 8 steps with internal frequency rate controlled by relative LFO potentiometer.

SYNC internal clock tempo can be set using the LFO frequency or sync mode to external +5V trigger input to arpeggiators modules like Elka Synthex or drum machines clocks like Roland Tr-808.

MEMORY :
- 16 memory slots
The memorized sounds can be also be played in sequence rotate, damn nice for some electro patterns also syncable to external trigger input clock. RAM is retained when switched off with a dedicated Cmos-chip like 5101 based board "programmeur" and a battery is soldered to it - just check out for acid leak.

MEMORY BOARD click to enlarge

FAMILY RELATED

	There are various KOBOL releases with different white knobs and a special custom version with.... accordion keys--gosh
	EXPANDER I the Kobol exists also in rackmount version, with more CV routing but lacks the great sequencer with sound rotate. EXPANDER II a module add-on with some new features like ring modulation, Sample and Hold, Envelope follower with many CV OUTS.
	RSF Polykobol II (1983) polysynth. A total disaster production and highly unreliable, this doomed machine sents the RSF company out of business. VIDEO
	MOS-LAB KOBOL EXPANDER a modern remake. I did not try this out but seems to be quite expensive. VIDEO
	MOS LAB 980 KOBOL VCO - clones oscilaltor for modular project
	RSF KOBOL VST PLUGIN: nothing for now, no samples libraries neither.

VIDEO CLIP SELECTION voici l'engin! memory test ZE kobol!

KOBOL MANUAL We do not have it, but there is an ONLINE version in FRENCH.

KOBOL SCHEMATICS IF you HAVE schematics or service for KOBOL keyboard, please get in touch for free sharing.

FOR SALE: NOT AVAILABLE

SPECIAL AWARDS: