Bastl Instruments Kastle V1.5

Full Description

Lo-Fi Mini Modular Synthesizer

The Kastle V1.5 builds on the success of the original Bastl Instruments Kastle synthesizer with a new and improved design. This new version of the Kastle combines a complex oscillator with an LFO and a stepped waveform generator. The unique lo-fi tones it produces is ideal for creating melodies and sounds on the fly. The internal sound card has been improved to ensure optimal audio fidelity and performance, resulting in vintage-style warmth and grit usually associated with classic analog synths. It boasts Pitch, Timbre and Waveshape control. The Pitch and Timbre controls come complete with offset and CV inputs, and a dedicated attenuator for dialling in your levels. The Wavehsape control also boasts offset and CV input for added flexibility.

In-Depth Modulation

The 3 main synthesis modes are comprised of phase modulation, noise modes, as well as track & hold modulation. There are three additional modes on the secondary oscillator output including phase distortion, tonal noise mode and formant synthesis. The waveshape is dependent on the synthesis mode, with it controlling the pulse width of the square wave output form the main oscillator. The LFO is voltage controllable, featuring a triangle and square output, as well as a reset input. The stepped waveform generator was inspired by the Runbler circuit (by Rob Hordijk) providing 8 different voltage in random order or in 8 and 16 step looping patterns for optimal versatility.

DIY Open Source Mini Synth

The synth was developed as an open-source DIY project that lets users expand on the factory configuration. At the heart of the BASTL Kastle V1.5 Synth are two Attiny 85 chips, which can also reprogrammed using Arduino. Each chip is dedicated to a different role, with one chip dedicated to sound generation, while the other handles the modulation.

Design & Construction

The ultra-compact design is extremely portable, easily fitting within your pocket and even your coat-pocket. Its robust enclosure is constructed from durable black and silver PCB material, ensuring it can withstand the test of time. It features dual I/O cv ports, which can be routed to a range of patch points. The main output also has the ability to drive headphones for private monitoring. It can also be powered via 3 x AA batteries or via USB power, with a handy two-position switch for selecting between the two. You can also exchange the LFO and OSC chips for advanced customisation capabilities.

What’s Included

• Kastle V1.5 synth
• 10 patch cables
• Sticker

Features

• Complex oscillator
• 3 synthesis modes on the main output: phase modulation, noise mode, track & hold modulation
• 3 more modes on the secondary OSC output: phase distortion, tonal noise mode, formant synthesis
• 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 16 step loop mode
• 2 I/O CV ports that can be routed to any patch point
• Main output can drive headphones
• 3x AA battery operation or USB power selectable by a switch
• Open source
• Possibility of exchanging different LFO and OSC chips
• Durable black & silver PCB enclosure