“Collection only please due to weight, and I haven’t got a box that is be able to fit it in.
Never gigged with only home studio use.
Please note this is working fully as a midi controller, but currently has no sound, it looks like it could just need a new battery after some Internet searches, but not that technical so don’t know.
Siel DK-80 Vintage Synthesiser 1985 Very Rare!. Low serial number of 3780, so was one of the first to be produced of this synth.
It’s 12 note polyphonic, velocity sensitive, the modulation wheel doubles as the pitch bend with a button press, you can reprogram some of the presets, I can’t remember how many possibly 10. If you know the Ex80 the expander version it’s basically 2 of them bolted together with a lovely feeling keyboard.
Works fully as a midi controller, with hardly any marks, especially since I bought it in 1985! That was the year it was made as well.
So there’s a few scratches underneath and a few of the screws could do with tightening and glueing, main problem is it has no sounds, apparently that could just be the battery, as I’ve had it done before and it worked, but I believe it’s soldered in. Quick fix if it’s just that and can do it.
Broken key as in photo – looked at replacing it, as a key on here is about a fiver, but as I’ve broken my shoulder just haven’t got the strength to do it, as its a heavy keyboard.
Oh the cartridge slot has had a spot of superglue on it to keep it closed as the spring needs repositioning or replacing, not a problem really if you haven’t got a cartridge.
Comes with case, black and red, new USB cable and PSU as apparently not many have them anymore.” Click here to visit listing on eBay
“DK80 SIEL Synthesizer. Condition is used. we are tested with headphone working !!!!!! we don’t have a another testing equipment. very clean . It will ship without original box. ” 
“DK80 SIEL Synthesizer. Condition is used. we are tested with headphone working !!!!!! no another testing equipment. very clean . It will ship without original box.free local pick up ” 
“SIEL DK80 synthesizer NO POWER SUPPLY Keyboard
“Used Siel DK 80 FM Synthesizer. From 1985. Very similar to the DX-7 Yamaha. I used this for a few years and it always worked well. Pulled it out of storage yesterday (a temperature controlled bedroom in my parents house) to test before selling and it doesn’t seem to work anymore, however. The unit makes somewhat loud (relative to the sound of the synth sound) buzzing sound, or the synth level seems quite low. Also, the synth doesn’t seem to want to change programs but honestly maybe that is simply because I can’t quite remember what to do to make that happen!” 
“SIEL DK80 synthesizer NO POWER SUPPLY Keyboard