Studio Electronics ToneStar 2600 is an ARP® 2600-styled synth voice, 31 years in the shaping, pre-patched like Pearlman’s prized 2600, and fully “outs to outs” modular. Connect CV / gate and twist ‘n’ switch, or pull its tones and voltages apart one 3.5mm cord at a time. 26 knobs, 7 switches, and 21 jacks make for complex and satisfying signal flow, color and collisions. If it gets reedy, route the triangle wave ‘roud the VCF.

Caswell Knowledge (circuit designer):

“The VCO is the same affair as the Oscillation, the Boomstar, and the Omega. It’s kind of a combination of Arp®, Oberheim® and Moog® circuits (sort of a greatest hits), time-tested, very stable—very good tracking over a very large range; certain parts have to be hand selected to achieve that level of performance.

Envelope FYI: The Tonestar Sustain control replicates the behavior of the 2600 and Odyssey: after the initial Decay, it continues to move (sink) very slowly, adding a little extra texture to the sound. It’s technically a flaw, but after digging out my Odyssey, it is for sure a desirable “quirk”, and the perfect companion to the 4072 filter.

Another bit of fun: the LFO is voltage controlled, so you can envelope, LFO, or otherwise modulate both the rate and the depth; the ADSR amount is also voltage controlled, so it can be manipulated by MIDI dynamics, MIDI volume, an LFO, etc. Greg [St. Regis] has decreed that anything must be patchable to anything, so some technically wrong patchings (for example pulse wave out to ADSR out) may often do unexpectedly interesting things.”