BASTL Instruments Citadel Alchemist

Citadel Alchemist is a patchable hybrid-synthesis based instrument that empowers you in discovering melodies and even harmonies despite being monophonic. Patch programmable sequencing via the control signals into the two PITCH MOD inputs opens up a world of melodic inspiration beyond classic arpeggios while staying in your preferred SCALE.

5 synthesis modes

The Alchemist has a carefully tuned wide timbral range spanning across 5 synthesis modes (FILTER, FM, HYPERSINE, SUPERSAW and GLITCHNOISE) accessed by main TIMBRE sweep that is refined by the RATIO control.

• The ENV macro knob affects different parts of the synth and sequencing engine to maximize musicality and it even lets you continually morph between the synthesis modes and access truly unique sounds.
• The timbral palette is further extended by the dual FX section which offers either a wide delay that will smear the arpeggios into echoed harmonies or a chorus-flanger-distortion-combfilter macro custom tuned for each synth mode.
• You can also access gliding rubber textures with the PITCH SLIDE macro that applies pitch envelope and portamento.
• You can customize its rhythms and scales with the web-based app.

Modulate anything

All main parameters can be modulated and tightly sequenced by the surprisingly powerful CV and GATE pattern generator alongside with syncable LFO that can be modulated as well.

Midi Inside Out

Citadel Alchemist is not just a sound box—it’s a powerful MIDI controller and sequencer when connected via the USB port on the back of the module. Send finely curated USB MIDI data to your DAW or USB MIDI device, and discover new ways of playing and interacting through a modular interface. Citadel Alchemist receives TRS MIDI via front panel and both sends and receives USB MIDI via the connector on the back of the module.

Make it fun

Do not write melodies! Let them emerge from the behavior you set-up by the patch interaction of various modulation sources.

From Kastle to Citadel

CITADEL is a Eurorack reimagination of the popular Kastle 2 semi-modular desktop device. The CITADEL comes with a full 3.5mm patch bay that offers the flexibility needed in the eurorack format while maintaining the strengths of the Kastle 2 allowing it to stand on its own, and yet let it truly shine when patched with other modules. We’ve also added switches for hands-on control of the pattern generator.

The Citadel provides the basic infrastructure needed to integrate eurorack systems within the context of electronic music making: headphone output, TRS MIDI input and sync, tempo generator with divider/multiplier, USB MIDI (from the back of the module), stereo mixing, integrated LFO and Pattern generator and effects.

All that makes Citadel the perfect module for smaller and beginner systems while the fun and unique creativity of the Kastle 2 firmwares: the FX WIZARD multi-effect processor and WAVE BARD sample player will earn its place in larger setups.

Like the previous Citadel modules, the Citadel Alchemist has a mirrored faceplate with the opposite side left blank for user labeling and customization — a feature we’re especially excited about as we partially open-source the Kastle 2 / Citadel platform, giving users more freedom to experiment. Core production, branding, and manufacturing elements remain proprietary, with full details to follow at launch.

• Width: 16HP
• Depth: 24mm
• Power: 60mA @ +12V  (w/o headphones) / 90mA @ +12V (w/ headphones) / 20mA @ -12V