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Kawai K4

“One key likes to stick.

I recently changed the battery and uploaded the factory firmware. There are a few scuffs on the body, but overall this is a great synth. Listing it to clear space in my studio.” Click here to visit listing on eBay

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Kawai K4

“Vintage KAWAI K4 16-bit Digital Synthesizer – LIKE NEW – Works Perfectly

Fully tested and working perfectly, part of which you can see in the attached video

Please zoom into the photos and watch the little video to judge the condition and working order for yourself.

What’s Included:

The KAWAI K4 61-Key Keyboard itself (upgraded to V3 OS/ ePROM at the Kawai facility in Southern CA)
The original KAWAI K4 Power Supply
The original KAWAI K4 User’s Manual, Wave List Manual and other supporting documentation
The original KAWAI K4 Carton with all original packaging
2 x 5′ New MIDI Cables
CD containing the Original Factory Library and Windows SendEX program only ever needed to reload the K4
New Internal Battery (Installed Sept, 2023) which should be good for up to 20 years
Handmade cover made by my girlfriend (who still loved me at the time) for my Juno 106but fits the K4 perfectly” Click here to visit listing on eBay

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Kawai K4r

“Includes original power supply.” Click here to visit listing on eBay

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Kawai K4

“Kawai K4 digital synthesiser. Kawai K4 Vintage Digital Synth (1989)This synth sounds great Can install your own sound banks via midi I have not used it to it’s full potential unfortunately In good working condition with no broken keys etc Can be heard working” Click here to visit listing on eBay

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Kawai K4

“The Kawai K4 is a sample-based digital synth that can make some interesting sounds. You can stack sounds with its multitimbral feature and warm things up with the filter. If you’re looking for industrial or lo-go types of sounds, this is a good synth to explore.

This particular model is in good shape with normal signs of wear (light scratches and scuffs). The display is still bright and legible. The keys, wheels, buttons, and sliders all work as they should. The only thing to note is the internal low-battery warning (pictured), so I’d advise replacing that soon. Please refer to the images for details.

The K4 comes with its original hard case. The case itself is a bit rough. There are scratches, peeling, and adhesive residue (from the previous owner), but no cracks or holes to note of. You can say it’s definitely done its job protecting the cargo.”
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Kawai K4

” Kawai K-4 synthesizer, all digital recorded acoustic instrument sounds and digital effects including drum sounds, velocity sensitive keys, very capable vintage keyboard, midi capable. Comes with original AC adapter, keyboard stand, will be shipped in the included Calzone hard case.” Click here to visit listing on eBay

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Kawai K4

“Kawai K4 16 Bit Synthesizer – Vintage 1980’s – Working Condition – Hard Case

*POWER LEAD MISPLACED*

Synthesizer Tested with Alternative Power Lead and Working Producing Good Sound Through My Guitar Amplifier

In Very Good Condition For Age Showing Minimal Use

Hard Case Showing Number of Scuffs and Metal Clips Rusted But Working”
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Kawai K4

“Very cool additive digital synth. I’ve had 2 of these over the years but thinning down my home studio and so letting this one go. Comes with power supply and original owner’s manual. All keys and buttons work, screen is bright and clear with no pixels missing. From my smoke free home studio.” Click here to visit listing on eBay

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Kawai K4

“Vintage KAWAI K4 16-bit Digital Synthesizer Keyboard.

Late 1980’s Kawai K-4 for your 1980’s tribute band, nostalgic rock band, 1980’s movie soundtrack sound source or similar. This was Kawai’s version of the popular Roland D-50. It has very usable organic sampled sounds, strings, pianos etc. The keyboard powers up and plays but the B2 key needs contact cleaning and won’t play until that is done. I also have ROM cards for it as well to add more programs/sounds. I have an old case for it as well that I can include. The case needs a new handle that’s easy to replace.”
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Kawai K4 Project Machine

“Welcome to this auction. I don’t have the original power supply. I tested it with a Power Supply that I use for something else. It does not turn on. This is from an estate sale, so I have no history. Sold for parts or restoration. Sold as is!!!” Click here to visit listing on eBay

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Kawai K4

“Kawai K4 Digital Synthesizer 1989 – Boxed with original manual and power adapter.

This hasn’t been used in a while so some of the sliders/buttons are a bit stiff, but they did get better with use.

Generally in good condition there are some marks on top which I’ve tried to capture in the pictures.

Priced to factor in the above points.”
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Kawai K4 Project Machine

“Sold For Parts or Repair, Lights Up, No Text, No Sound, The top has a scuffs and scratches. No Power Adapter, No Accessories. Sold As Is, No Guarantee on Any function. No Returns, See Photos” Click here to visit listing on eBay

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Kawai K4

“Kawai K4 16 Bit Digital Synthesizer

Has some dings and scratches but works fine
Comes with non-original power supply” Click here to visit listing on eBay

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Kawai K4

“1989 Vintage KAWAI K4 16-bit Digital Synthesizer. Good Condition. Comes with power cord. Works and functions as it should. My uncle used this to make music and gave it to me I just don’t have time to learn. Pet free. Smoke free. Has a cover that comes with it too. ”
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Kawai K4

“Kawai K4 Sythesizer.

61 key, 16 bit digital synthesiser.

Good condition and fully working with some superficial wear and tear.” Click here to visit listing on eBay

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Kawai K4

“Nice vintage synth in good working condition. Includes reinforced gig bag with shoulder strap, power supply and instruction manual.” Click here to visit listing on eBay

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Kawai K4

“Refurbished / renovated Kawai K4 with new flourescent green LCD display. Replaced most of the capacitors on the main board, installed a new volume slider which slides better and a new headphone opamp. Installed the latest Firmware chip V1.4 and new CR2032 battery. Comes with manuals and original Kawai power adapter. Ships via UPS.” Click here to visit listing on eBay

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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

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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

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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

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Kawai K4

“Vintage Kawai K4 Digital Synthesizer

Has some dings and scratches but works fine

Comes with non-original power supply” Click here to visit listing on eBay

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Kawai K4

“Some cosmetic scratches (see images), yet mainly in beautiful clean condition. Bright keys make this keyboard look and feel almost new.” Click here to visit listing on eBay

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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

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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

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Kawai K4

“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.” Click here to search for synths on eBay

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Kawai K4

“Very good condition. Everything works 100%. Just has a couple light scratches which you can see in the pictures above.” Click here to search for synths on eBay

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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

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Kawai K4

“1989 Kawai K4 Vintage 16-bit Digital Synthesizer A True Classic!” Click here to search for synths on eBay

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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

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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

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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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