Kawai K4R
Digital Synthesizer Module (1989)

Rackmount module version of Kawai K4 synthesizer with cycled waveform wavetable and resonant filters.

RACKMOUNT the main panel features a 16 x 2 lines LCD display, 32 buttons and a data slider.

Back panel terminal connectors:
- Midi Interface
- main analog signal out
- 6 assignable analog outputs.


Power supply PSU 12V at least 500 mA polarity negative center - original model is PS-121G.

TECH CPU 8-bits UPD 78310G manages 16 voices polyphony based on samples synthesis DMS tone generation. DAC is a Burr Brown PCM66P. A basic K4R patch is composed by 1 or 2 PCM samples or "sources" that can routed to filter in 3 possible modes: normal, twin or double.

Matched pair of sources can be ringmodulated by DIGITAL AM PROCESS in 2 ways: A- source 1 -> source 2 B- source 3 -> source 4 Ring modulation HEAR

PCM WAVETABLE internal 16 bits ROM contains 256 DCO waves - Full PCM list HERE
Internal K4R ROM is organized into 2 categories:

96 PCM DC digital cyclic: mathematically precalculated fundamental and basic waveforms e.g sinusoidal, analog square, voice formants, organ additive and some short transients. 160 PCM acoustic samples categorized into 4 subgroups: drums, multi, block and reverse & loop.

PERFORMANCE system manages up to 8 parts all variable settings:

- split zone - volume gain - transpose semitones - Midi channel assign - velocity thresholds

FILTER IC K008-FP handles 2 digital resonant filters featuring a -12 dB slope each.
Filters can be chained in serial or parallel mode and scream at high resonance value, which is way quantized into 7 scaled steps.

HEAR filter cutoff

ENVELOPE 6 EGs:

- 1 X EG FILTER 1: 3 segments + 1 time level - 1 X EG FILTER 2: 3 segments + 1 time level - 1 X EG (for each SOURCE) amplitude a 3-segments + 2 time levels.

 

LFO single delayed main modulator (shapes: triangle, saw, square and random) and 3 destinations (a simplified second LFO acts as a vibrato sharing same LFO1 waverform )

- LFO to pitch - LFO to filter 1 - LFO to filter 2 HEAR random LFO

MEMORY:
- 64 RAM slots for patches
- 64 RAM performances
Sounds and setting may be saved to standard Midi sysex dump or recorded to Kawai RAM cards model DC-16 or DC-32

- Battery replacement: simple CR2032 in a holder, so soldering is involved. click to enlarge pic

 

OS UPGRADE Internal EPROM 27C512 64 kb (P207 for K4r / P206 for K4) latest should be 1.4.

DOWNLOAD BINARY EPROM

 

EDIT many programmers for computer:

- Soundquest (commercial PC/MAC) PIC - Sounddiver (out of business) - K4 WIN (shareware old PC) PIC - K4 patch editor (freeware old PC) PIC - K4 editor (freeware ATARI ST) PIC - Musicode K4 Voice Development System (? ATARI ST) - K4 editor (shareware Commodore AMIGA) PIC - K4/K4R Ipad editor (commercial IOS)

K4R RELATED FAMILY:

	K4 61 keys keyboard version, same but it features an effect DSP, but lacks extra analog outs. K4 then has been replaced by K11 and Gmega module.
	XD5 similar to K4r, but different wavetable. XD5 is aimed to percussions and drums sounds.

 

VST PLUGIN / SAMPLED VERSION there are some free and commercial samples set:

VIRTUAL K4 offers a kind of emulation based on samples. However 2 major problems: It needs an old AWE32 soundcard for DCF filter emulation and It does not seem to work from Windows XP to higher.

 

ADVERT GALLERY: