“Owner for almost 30 years offering truly barely used (VERY LOW hours), studio use only, never gigged, KAWAI K4R 16-bit Digital Rack MIDI Synthesizer Sound Module, circa 1989. These are hard to find and have a unique, versatile sound.
Unit has been fully tested including LCD display, all buttons and sliders, audio outputs, and MIDI ports. Internal battery recently replaced. Includes original genuine Kawai (made in Japan) power supply AC adapter and printout of instruction manual.” Click here to visit listing on eBay
“Please note that there is some material on the front panel back panel surfaces. I’ve attempted to capture it in the photos – please review them carefully. This gunk is the reason it’s listed as “good” condition. Really, you can’t notice it in the rack, but I wanted to call it out so that the buyer isn’t surprised.” 
“Kawai K4r Synth,. Condition is Used.
“Used vintage k4. This is a really light weight rack, don’t let the appearance fool you. The rack has plenty of cool sounds on board waiting to be played, and theres more patches on the internet too (just make sure the memory protect is off before sending patches, I made that mistake once) Sounds great!” 
“Kawai K4R Rackmount Synthesizer 16BIT module . Condition is Good Used. Power supply included.”
“Kawai K4r 16-Bit PCM Digital Synthesizer Rackmount. Condition is Used.with two Ram cards”
“The K4r was one of my favorite synthesizers in the 90’s. It has a resonant filter, so unlike many of the ROMplers from back then, this synthesizer can make some really cool and aggressive sounds. It can sound a lot like a D50 because of the ability to layer 4 different waveforms, but it is a LOT easier to edit from the front panel, so I tended to use it a lot more. The Basses, Organs, synth pads and percussion samples were all over my trip hop tracks back in the day. In fact, I got the idea to buy this when I saw it in the Sneaker Pimps studio. These days I see Legowelt has one, and though many prefer the K1 because of it’s lower bit rate and use by some of the old warp artists, the filter on the K4 makes it a way better synthesizer all around.” 
“Up for sale is this clean and nice Kawai K4r Synthesizer Module. This is a highly collectible pieces which was used by The Chemical Brothers and ATB. Packed with your favorite vintage-style warm and fuzzy synth sound, this K4r sports 16-bit preset PCM samples of acoustic instruments, perfect for the weird industrial type sounds that can still be useful in lo-fi, big-beat and trip hop music styles. It also features a digital filter section which makes it even more versatile and playable.
“In good condition”
“Up for auction is a Kawai K4r Synthesizer Rack Mount w/ Power Cord. Works great, has cosmetic wear which is shown in pictures. ”