make / manufacturer: Alesis
model name / number: QS6.1
I really liked this keyboard a lot, but unfortunately there seems to be an issue with the pitch wheel that causes the piano to constantly go out of tune. At first it would just be that the pitches for the different notes were not correct, which is easy enough to fix by restarting the keyboard, but now it will often go out of pitch in the middle of a single note. It creates a weird warped wacky sound to the keyboard. Maybe that’s something you would like?? Or maybe you can somehow fix the pitch wheel. Either way it’s too much for me to bother with. Comes with foot pedal, reference manuals, gig bag, and discs shown in pictures.

Unfortunately, I won’t be able to invite you in to try it out, due to Covid, but it works as described.

$100 or Best Offer. Pickup only. Serious inquiries only, please. I will not respond to emails that say, "call me."

From vinatgesynth.com:
The QS6.1 is a 64 Voice Expandable Synthesizer and is a much more improved version of the QS6 QuadraSynth. With double the sound memory, the QS6.1 has 16MB of digital ROM samples, double the expansion capabilities, double the real-time control sliders, and a much improved and larger LCD display screen. The QS6.1 has a vast set of sounds containing a library of 640 programs and 500 multitimbral mixes. Really amazing pianos, orchestral sounds as well as vintage synth sounds, strings, brass, winds, guitars, drums, percussion loops and groove patterns can all be found here.

The QS6.1 features 64 multitimbral parts over 16 MIDI channels. That's a lot. And since it's 64 voices polyphonic, you can arrange some pretty complex and complete music, from full orchestras to trance dance tracks, beats and sfx heaven! The keyboard can be split into 16-zones! Control the volume, panning, transposition, effects level and more of each channel independently. Four on-board edit/control sliders are assignable to most modulation parameters. Onboard multi-effects based on the QuadraVerb 2 include reverb, chorus, distortion, EQ, delay, rotary speaker simulation and more. These are on four independent busses so it's like having four FX units!

Powerful MIDI implementation suits the QS6.1 for any studio situation. But it has more! It can connect to your Mac or PC using its RS422 or RS232 ports. The QS6.1 comes with a CD-rom (Mac/PC) with Alesis' Sound Bridge and FreeLoader applications, plus programs for sequencing, editor/librarians, notation, extra samples, programs and mixes, sample sequences, demos and more.