TONESTAR 8106, an ARP® 2600-inspired complete synth voice, infuses Tim Caswell's "Jupiter to Juno" filter alchemy — a 6db/oct hi-pass filter followed by a recreation of the Roland® IR3109 module—into our Tonestar 2600 platform; this chirpy yet full-bodied 8106 model is also fully #OutsToOuts modular featuring 27 pots (one more than the 2600 model for the high-pass filter), 6 switches (one less, sacrificing resonance modulation for that high-pass filtering), and 21 jacks. If the Tone★ 8106 thins somewhat with resonance excess, route the triangle wave 'round the VCF with the "NO VCF" switch setting, and keep this juicy reimagining of the Roland® IR3109 module boomin' and gloomin'. Click for nearly thrilling examples in the Out to Outs/Interesting Patches pdf, and read more about the 8106 filter here.
Knowledge from 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 exacting performance.
Editors Note: This module is a TONESTAR—its own thing—and not a 2600 clone attempt;
nevertheless, the Tone☆ tugs lovingly at times on the sleeve of the 1970's era classic.
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 (which we mistakenly titled a 4075 in the Boomstar Modular line).
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 produce unexpectedly interesting, x-mod/notch filtering—quite pleasing effects.
The Tonestar was Greg's concept, but as I understood it, the goal was a single oscillator, 2600 VCF (initially), pre-patched and yet fully modular classic synth voice, at a specific size, wielding every trick we could cram in. Main use would be as a go-to bassline/lead tool, or a premium quality, entry-level, complete synth module, for root-to-leaf sound design, and multiform analog exploration/expression.