Bastl Instruments Intros Kastle Drum Mini Modular Groovebox

Bastl Instruments has introduced the Kastle Drum, a new version of their Kastle mini modular synth that focuses on algorithmic industrial glitchy drums.

Here’s what they have to say about it:

“The Kastle Drum is a mini modular synthesizer with a headphone output, 2 in/out ports for interfacing other gear, and it runs on just 3 AA batteries. It is ideal for beginners in modular synthesis, but it will add some quite unique functionality to any modular synthesizer system. It delivers the fun of modular synthesis at a low price and fits into your pocket so you can play it anywhere!”

Kastle is an open source project, with all resources obtainable from GitHub, but Bastl notes that they can’t provide haxx0r end-user support. 


  • 8 drum synthesis styles
  • ”noises” output for less tonal content
  • DRUM selects drum sounds
  • acceleration charge dynamic envelope
  • decay time
  • PITCH control with offset and CV input with attenuator
  • voltage-controllable clock with square and triangle output
  • stepped voltage generator with random, 8 step and 16 step loop mode
  • 2 I/O CV ports that can be routed to any patch point
  • the main output can drive headphones
  • 3x AA battery operation or USB power selectable by a switch
    open source
  • durable black & gold PCB enclosure

Feature Overview:

Pricing and Availability

The Kastle Drum is available now for €90.

9 thoughts on “Bastl Instruments Intros Kastle Drum Mini Modular Groovebox

    1. Actually, after hearing more demos, I have to take my words back. It sounds quite interesting. It can even produce some nice punchy kicks and overall sound is much more clear, than of the original Kastle. Now I want it!

    1. What dotcom users were saying about Eurorack for years. And those mini cables make it very easy to prototype with a breadboard. Which is very much using it as a tool, not a toy. a much more valuable and expandable tool than a huge chunk of commercial products out there.

    2. i’ll never understand why people get all pretentious about musical gear being “toys”. Go “play” on your $5000 synth from your high horse 😛

    3. It s not though.sound design is sound design, it doesnt matter the source. I see endless possibilities with this to layer with regular beats in a ,let’s say, techno context. Filter it, sidechain it, repitch it in Ableton. This is perfect.

  1. I like randomness, glitch, and discovering patterns and sounds so this looks really fun to me… if only for random jamming or sampling. I enjoy Bastl’s small, battery powered gear a lot, I could pair it with my microgranny(s) and DUDE mixer. Will probably pick one up once they restock.

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