KORG MS-10

via this auction

Oberheim Matrix 6R

via this auction

Vintage ARP "Axxe" 2310 Synthesizer

via this auction
"The ARP "Axxe" was introduced in 1975, mainly to compete with the Minimoog. It is analog, monophonic and simpler in design (single VCO) than the Moog but I found it fairly easy to setup and get good quality usable sounds out of. Smaller in size; 37 note keyboard.

This early version (serial 739) has the Moog type ladder filter that was the source of patent infringement problems for ARP. It was removed from later models apparently avoiding a lawsuit."

OBERHEIM MATRIX-6R

via this auction
"The Matrix-6R is basically a rack-mounted Matrix-6 without the keyboard. It featured 6-note polyphony and digital osciallators. Each voice has two DCOs, a VCF, three envelope generators (5 stage: Delay, Attack, Decay, Sustain, Release), two ramp generators (simple envelopes), tracking (not just for the keyboard but for remapping any modulation source), portamento and FM controls, three LFOs, and two VCAs. Along with other "Matrix" products from Oberheim, the Matrix-6R featured what Oberheim called, "Matix Modulation System", which makes for very flexible and powerful modulation programming. With this much programmability it is unfortunate that, like the Matrix-6, the only user interface is a single slider and a keypad. However the Matrix-6R does give you 6 individual LEDs that light up for each voice that is played. It also features MIDI mono mode where each voice has its own MIDI channel (very useful for guitar controllers)"

KORG POLYSIX

via this auction