Kawai K4

“Back for sale! Kawai K4 with new flourescent green LCD display, mostly new capacitors on main board, new volume slider, and headphone opamp.

Includes original manuals and Kawai power adapter.” Click here to visit listing on eBay

Kawai K4

“Most of the capacitors on the main board have been replaced with low ESR 105C Panasonic, and I replaced the 1uf electrolytes with much improved film to further reduce noise in the overall circuit. I replaced the NJM4556D headphone opamp with JRC2068DD which has faster slew rate and higher bandwidth. All these updates added more clarity on the high end (while still keeping the 16 bit K4 character) and with the mods it sounds better than the original K4 when I did a direct comparison against the unmodified one.

I replaced the LCD display with a much better one and installed a 10k trimmer resister. To adjust the display brightness simply insert a screwdriver in the + slot of the trimmer resister and gently turn however I already adjusted it to the best luminosity. I have also performed this modification to my other K4s since it’s a great improvement over the original display.

I installed a new volume slider potentiometer. It is now much smoother sliding than the original. And I also installed the latest Version 1.4 OS chip, purchased new.

I have found much (but certainly not all!) of what the K4 is capable and will keep the patches I designed after the circuit upgrade.

There are individual buttons to select or mute each layer which means that parameter access/sound design is relatively quick. Immediate muting lets you quickly hear the layer you are working on which is important for sound design. The K4 excels at resonant transcendent beautiful digital crystalline pads and the resonance is so high and fizzy that it can devolve into sizzling distortion so I never use maximum but it makes for a very interesting unique sound. Click here to visit listing on eBay

Kawai K4

“Vintage KAWAI K4 Synthesizer Keyboard Vintage Synth is a unique sounds digital keybaord. Some may describe it as dirty digital but, its something special.

All the keys, buttons, sliders, and outputs work as they shoukd with no issues.

Comes with printed owners manual, service manual & original power supply.” Click here to visit listing on eBay

Kawai K4

“Kawai K4. Condition is used, some minor wear marks but overall, good for its age. Mono output is a bit temperamental, crackles occasionally so needs attention. Universal power lead included, not the original. ” Click here to visit listing on eBay

Kawai K4

“For sale is my Kawai K4 synthesizer. It is in full working order and great condition for it’s age. There are a few marks here and there but overall I would say 7/10 for cosmetic condition. A few buttons need a bit of a firmer press but all working correctly.

This is a fabulous synth for Lofi music production and it is renowned for having a great resonant filter. Whilst the pianos leave a lot to be desired the pads and filter sweeps really make up for it! A very underrated synth.

It comes with a generic power supply, print out of the user manual and I have the last O.S 1.4 chip which is an easy socketed procedure so no soldering. I also purchased the Greytsounds patch collection sysex files. I found loading them via the free midi-ox application a breeze and there are some stunning patches in each bank. These will be emailed to winning bidder as the 7 bank files are no more than 200kbytes.”
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Kawai K4

“Item is used and has some surface wear. Comes with after market power adapter. Plug in a pair of headphones and be amazed by the sounds this thing can make. No case or card. Sold as pictured, some dust and 4 keys have the notes written on them.” Click here to search for synths on eBay

Kawai K4

“1989 Kawai K4 Vintage 16-bit Digital Synthesizer Korg M1 Yamaha SY55 w case NR. Condition is Used. Shipped with USPS Parcel Select Ground.

Very good condition. Everything works 100%. Just has a couple light scratches which you can see in the pictures above. No reserve auction, good luck.”
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Kawai K4

“Minor crack on front/bottom right side of body (pictured) does not effect integrity. Serviced once decades ago for dead key. Shipped with non original power supply. Has expander cartridge (pictured).” Click here to search for synths on eBay

Kawai K4

“Kawai K4 16 Bit 80’s Vintage Digital Keyboard Synthesizer. Used but good condition, plays perfectly and has lots of great sounding settings to choose from! All the keys work and all the settings work. Has a nice display screen and everything is in good condition. Comes with the power supply. The bottom of it has some scratches but nothing that affects the sound or playability of it.” Click here to search for synths on eBay

Kawai K4

“This listing is for a very nice Kawai K4 classic digital synthesizer. Sounds are great as you’d expect. All functions tested work as they should, every key tested – good practice for my chromatic technique!

Please note the small chips in the lower part of the front of two keys, the only issues of note.

This will be supplied with a compatible AC adapter.” Click here to search for synths on eBay

Kawai K4

“KAWAI K4 KEYBOARD SYNTH

I HAVE NEVER USED THIS, I GOT IT ABOUT 20years AGO.

THERE IS NO CHARGER FOR THIS KEYBOARD

I HAVE TRIED TO PLUG IT IN USING A CHARGER FROM MY RADIO, BUT IT DIDN’T SEEM TO BE WORKING.”
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Kawai K4

“Up for auction is this KAWAI K-4 vintage Digital Synthesizer

61-key Keyboard

1988

Made in JAPAN.

Excellent Professional Vintage Instrument.

Great Condition ! Very Clean.

All buttons, sliders, keys, Outputs, OS system

Tested and works Great, Sounds Really Amazing !

Used only in home Studio.

Comes with a Power supply”
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Kawai K4 Project Machine

“Kawai K4 16 Bit Digital Synthesizer Keyboard No Power Supply. Condition is Used. Includes soft case – but as you can see in the pictures, one side of the shoulder strap for the soft case has broken off. The keyboard will NOT power on – but I do not have the power cord. This may be a simple fix, but maybe not. I simply do not know.”
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Kawai K4

“Kawai K4 16 Bit Digital Synthesizer Keyboard Works Great No Power Supply. Condition is Used. Includes soft case – but as you can see in the pictures, one side of the shoulder strap for the soft case has broken off.

This great sounding keyboard is in excellent working, excellent sounding shape. The power supply is not the original, but it works perfectly with this piano. The keyboards keys are all working and the selector buttons are switching through the various preset sounds as they should be. The keyboard shows some typical signs of cosmetic wear from use, but still makes a great overall impression.”
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Kawai K4

“KAWAI K-4 Vintage 16 Bit Synthesizer 61-Key Keyboard. Made in JAPAN – 1989 – nice working condition for nearly 30 years old – aftermarket power supply ships with synth! These are becoming more and more sought after!” Click here to search for synths on eBay

Kawai K4

“Kawai K4 16 Bit Digital keyboard Synthesizer and stand. has 61 keys with velocity and aftertouch. The main panel features a 16 X 2 lines display, 28 buttons a data slider. On left side 2 wheels for pitch bending plus a modulation assignable to LFO rate/ filter or filter cutoff. Comes with original ac power adapter, foot pedal and jack cable.

Keyboard is in great shape. Shows less then normal wear on bottom and sides for it’s age. All keys and buttons look to be in great shape. Please see pics for condition. ”
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Kawai K4 Project Machine

” Vintage Kawai K4 Digital 16bit Synth from the late 80’s.
Synth looks good with some minor wear, all keys seem to work(one has minor chip) see pics.
Synth boots up but only has one sound, i am guessing someone changed the battery and lost the factory presets and never loaded them back on, a easy fix if you know how and a free download.
The biggest issue is the Volume slider has a lot of noise, it works but not right, maybe just needs cleaned but may need to be replaced.
If you are handy with these here is a chance to get a great deal on a very cool vintage synth.” Click here to search for synths on eBay

Kawai K4

“Kawai K4 synthesiser, does need some attention. There are 3 sound cards with the keyboard, although I think there are only sounds on 2 of them, there also only appears to be 1 sound when you play the keyboard with no card in, (may need the factory sounds reinstalling). There are also some keys that do not work, and these are marked on the photo’s. I am fairly certain that I have the user manual, but will check and update this listing, (it is freely available on the internet if I haven’t). There are also a couple of the weights missing from the underside of the keys, (again shown on photo’s), I may still have them, but not guaranteed.” Click here to search for synths on eBay

Kawai K4

““This item is cosmetically in overall very good condition for its age. There is normal wear such as scuffs/scratches and debris. All the keys appear to be intact. There are no readily visible chips/cracks to note.” Click here to search for synths on eBay