Bastl Instruments Kastle 2 Alchemist

Impressive sounds with a fiddly attitude

With the Kastle 2 Alchemist, Bastl Instruments presents an experimental, patchable mini synthesizer. At first glance, it offers all the typical synthesizer parameters you would expect from a full-featured instrument. The compact synthesizer’s digital sound engine delivers an impressive range of possibilities, including five synthesis modes: Filter, FM, Supersaw, Hypersine, and Glitchnoise. These modes provide advanced features such as four VCOs, Feedback FM, Raw Waveform, Ring Modulation, Track & Hold, Noise + T&H, a stereo filter, and a transient shaper. The oscillator covers a pitch range of ±3 octaves and is complemented by an integrated quantizer with user-definable scales, which can be edited via the web app. Internal modulation options include a macro envelope, a synchronizable LFO with two waveforms, and a CV/gate pattern generator, which can also be edited using the free web app. The effects section puts the finishing touches on the Alchemist’s sound: turning TIMBRE Mod to the left introduces a delay, while turning the control from the center position to the right creates a smooth transition from chorus to flanger to distortion. The Kastle 2 Alchemist produces a surprisingly broad sonic palette, ranging from classic analog-style tones and FM-like sounds to waveshaper textures and experimental, atonal timbres.