TECH CPU 8-bits UPD 78310G manages 16 voices polyphony based on samples synthesis DMS tone generation. DAC is a Burr Brown PCM66P.
STRUCTURE a basic K4 patch is composed 1 or 2 PCM samples or "sources" that can routed to filter in 3 possible modes:
RINGMODULATOR matched pair of oscilaltors sources can be ringmodulated by DIGITAL AM PROCESS in 2 different manners:
- source 1 modulates source 2
- source 3 modulates source 4.
Ring modulation HEAR.
PCM WAVETABLE internal 16 bits ROM contains 256 DCO waves split 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.
Full PCM list HERE
PERFORMANCE system manages up to 8 parts all variable settings:
- split zone
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.
Another useful function is the Key tracking mode at 50% cutoff value to lower or higher octaves.
ENVELOPE 6 EGs:
- 1 EG FILTER 1: 3 segments + 1 time level
- 1 EG
FILTER 2: 3 segments + 1 time level
- 1 EG (for each SOURCE) amplitude: a 3-segments + 2 time levels.
TIP: The sounds can be played following 8 different non-editable velocity curves.
LFO single delayed main modulator (shapes: triangle, saw, square and random) and 3 destinations:
- LFO to pitch
- LFO to filter 1
- LFO to filter 2.
A simplified second LFO acts as a vibrato sharing same LFO1 waverform.
random LFO exemple HEAR.
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
- UPPER - magnify: Battery replacement: simple CR2032 in a holder, so soldering is involved
OS UPGRADE Internal EPROM 27C512 64 kb (P207 for K4r / P206 for K4) latest should be 1.4.
DOWNLOAD BINARY (thanks to Alfred Semper).
EDIT there are many programmers for computer like
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) PIC BELOW
K4R RELATED FAMILY:
K4 61 keys keyboard version, same but it features an effect DSP, but lacks extra analog outs.
|| 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:
|A kind of emulation based on samples.
However 2 major problems:
It needs an old AWE32 soundcard for DCF filter emulation
It does not seem to work from Windows XP to higher.