1989 Kawai K4 - Digital Resonant Filter (DCF) Test

video upload by ChrisLody

"I recently bought this vintage Kawai K4 imported from the USA because I'd heard good things about it. I was most intrigued though by the fact that it's a polyphonic synth with digital resonant filters (as in written purely in code rather than controlling any analog filtering) which makes it one of the first on the market to offer this alongside the Yamaha SY77 and Emu EMAX II which I've been informed all launched in 1989. The Roland D50 had something that sounded very filter like with it's 'TVF' back in 1987, but this was only available on square and saw waves and was more of a mimic of a filter. So I'm told anyway, I never used any of the other gear I just mentioned 😄

S considering that it was this early in the game I was very interested to hear what it sounded like but couldn't find any other filter demos on YouTube, so here's mine. I was planning something more involved showing how to edit a patch etc, but I got carried away playing and ran out of time. Maybe in another video.

All the examples shown use the brightest saw I could find (the waveforms are sampled) in a single slot with a single filter. If setup correctly a single patch can have 2 filters either in parallel or serial modes but I haven't experimented with that yet."