Venus Theory is one of the lucky people to have their hands on the Genki Instruments Katla, the Icelandic volcanic synthesizer priced around $6,000 (yes you did read that right).
As well as parts hewn out of the Icelandic Katla volcano, hence the name - it has five single oscillator voices with a paraphonic architecture, each with individual level, waveform and octave controls for each.
The resonant filter has low pass and band pass modes, self-oscillation and a wave folder. Modulation has some unusual routings, with a "volcano" (of course) LFO shape and a Skrida control that randomizes envelopes and levels per note.
As well as user presets it has a system which recalls patches per section, effects include reverb, analog drive and tape-style detuning, and recent firmware adds MPE.
We explore it together - and if you want to get a sense of what it can sound like - we have a set of Custom Decent Samples from Venus Theory for our own Decent Sampler UI available here:
https://www.patreon.com/sonicstate/posts/18-genki-katla-165744043
(Star Tier and above)
And For YouTube Members (16-bit)
https://www.youtube.com/post/UgkxnfLQo5syVQ4TqoeqLzWRoP4TmbTHG9ff
And Venus Theory has his own Free Tephra instrument:
https://venustheory.gumroad.com/l/vttephra
More information on the Katla:
https://genki.is