via this eBay listing
"Gorgeous blue synthesizer. So cute and I hate to part with it but i've got my dream keyboard and don't have room for another. 4 operator fm synthesizer (yamaha chip) with the variable waveforms as seen in tx81z, dx100 etc. Easy to edit parameters with the slider, and there are performance sliders for both envelope times and timber. the keybed feels really nice and has aftertouch which can be routed to a handful of parameters. Selling the keyboard with the mcr-02 memory card which you can store extra patches on. A quirk of the 707 is that the memory card is for some reason required to reboot the synth if the internal backup battery dies (the battery that keeps the patches saved after power down). I put a fresh battery in recently so it shouldn't be an issue for years. I've also replaced the tact switches for the main cursor and value buttons; you rely on these heavily to edit patches and they wear out faster than the others. In terms of physical condition, there's a crack in the plastic screw hole on the back of the synth (pictured). i superglued this cracked piece into place so it's a little more sturdy. there's about 2 tiny scuffs around the perimeter but otherwise it's a beautiful bubbly vessel of periwinkle blue. there are posts on the side of the synth for a keytar strap if that's your thing."
