The K4 is the successor to the Kawai K1, but with higher-quality waveforms and a digital filter added. It was also produced in rackmount form lacking the effects DSP as the K4R.
It has an 8-bit processor to power what Kawai calls "DMS tone generation" and a patch can be built using one or two samples. It can save patches to a memory card, working with either a DC-16 or DC-32 RAM card.
The K4 uses a 12-volt external power supply rated for 500 mA of current (model PS-121G).
Year Released: 1989
Keyboard: 61 keys with velocity and aftertouch
Polyphony: 16 notes
Multitimbral: 8 parts
User Patches: 64
User Performances: 64
ROM: 256 16-bit PCM waveforms
Effects: two digital resonant -12dB filters, plus reverb, delay, chorus, flanger and distortion/overdrive via DSP.