It runs on three AA batteries. It’s not really much bigger than those three AA batteries. And yet somehow, it’s a modular. You can use it like a synth, or even plug it into other gear. It’s the Kastle, from Bastl Instruments, those wizards from Brno, Czech. And at 65€ (79€ fully assembled), it’s going to sell like hotcakes. (Makes me hungry for hotcakes, even.)

The heart of the Kastle is a complex oscillator with three modes – phase distortion, phase modulation, and track and hold modulation. Where this gets modular is the way you control it – pitch, timbre, and waveshape can all be patched, as well as the LFO. There are two patch points.

And it’s open source hardware. (Actually, I think Bastl are one of the few other makers apart from us with MeeBlip making end user music gear. But if I’m wrong – if you are – give us a shout!)


complex oscillator
3 synthesis modes: phase distortion, phase modulation and track & hold modulation
pitch control with offset and CV input with attenuator
timbre control with offset and CV input with attenuator
waveshape control with offset and CV input
voltage controllable LFO with triangle and square outputs and reset input
stepped voltage generator with random, 8 step and loop 16 step mode
2 I/O CV ports are available and can be routed to any patch point
the main output can drive headphones
3x AA battery operation with power switch
open source
possibility of exchanging different LFO and OSC chips
the pattern on the sides changes and every unit is an original



The Bastl team have a busy weekend, as this is rolling out in both Brno and Brooklyn. (There are two locations on the map that weren’t routinely put together before the rise of Bastl.)

If you’re in New York, you might have already bought these, as yesterday it went on sale:

Detective Squad Party
11 Stanwix Str.11206 Brooklyn, NY

But it’s also coming to Queens as of today, with an event running Saturday and Sunday:

Machines in Music
Knockdown center
52-19 Flushing Avenue
Maspeth, NY 11378

Still, dear Czech friends, no need to fear being left out – of course, it’s also at Bastl’s own Noise Kitchen store in Brno. I’m trying to convince this crew to bring some down to Lunch Meat Festival in Prague on Friday, so anyone else going, feel free to join the chorus.

For the world not in New York City or Brno, you can also order and have it shipped from Czech via the friendly Czech Post.

So, that’s a matter of walking down Kounicova 23 in Brno, or … sitting right where you’re at now on these here Internets and making it rain some synthesis:

79€ assembled, or get the kit version for 65€. Outnow.