The 1530 uses miniature pencil-sized vacuum tubes that were developed and refined by the Russians over 60 years ago. They are low current and low voltage devices, so they don’t need the high-voltage power supplies that are required for most other vacuum tubes.
SSL President Doug Slocum calls the new module “a wild blend of vacuum tube warmth and distortion, along with an incredibly useful VCA that is so much more than the sum of its parts.”
“While it’s a surprisingly good VCA, it really shines when it’s over-driven – rounding and folding the input waveforms like nothing else available,” he adds. “In some modes, it’s prone to wacky self-oscillation that can be made to lock onto the harmonics of the input waveform in cascading howls.”
The module builds on a design licensed from Ken Stone (CGS), who’s well-known in the synth DIY community for his modular designs.
SSL has added LEDs behind the tube, to visually emulate the warm glow of the filament, and pulsating blue LEDs that simulate tubes as they are being driven by control voltages – visible through a custom acrylic window.
Here’s a video demo, via synthesist John L Rice:
Pricing and Availability
The Synthetic Sound Labs 1530 Tube VCA / Timbral Gate is available now for $295 USD.