I just heard from Aaron Hunt, the head of H-PI Instruments. He says that their Tonal Plexus MIDI controller has been shipping since last October, in the 2-octave and 4-octave form.
$1292 is really not much to pay for a PROGRAMMABLE microtonal keyboard that can do ANY scale, with 422 keys (!). In fact, that’s a steal.
Think about it–the next instrument up that can do this, the Haken, costs THREE TIMES as much as the Tonal Plexus. Not sure if the C-Thru can do programmable scales.
Plus, microtonality makes it more flexible than the other alternate keyboards, which H-Pi lists here.
(No idea the Terpstra cost $10,000. Still no idea if they shipped any.)
I am very tempted to get a 2-octave Tonal Plexus. No, this is not an advertisement. It would be interesting to see if it can give full effect with popular MIDI-CV converters like the Kenton.
Aaron’s site also has a section on microtonal keyboards of the past. READ IT.