AS 259
Complex Oscillator

Updated on 30 May 2025. Built it in v5.0 and includes performative enhancements. See notes below. Enjoy! 

Here is something new - I like the sound, and complexity of Don Buchla's various musical instruments. The Buchla 259 Complex Programmable Oscillator is no exception. After looking at some different documentation, various YouTube videos and the module's faceplate I went ahead and made my own version as a Bitwig Studio preset. My approach was to capture as much of the timbral variation and control as possible. You can complete the programmable portion through Bitwig's extensive routing and modulation options.

Recommended usage:

1. Start with the preset as shown below.

2. Adjust the Mod level and activate one, or more of the modes (Phase Lock, Timbre Mod, AM Mod, or FM Mod). Try the Mod Freq to adjust the modulation rate. With the Lo/Hi button disengaged the frequency range runs between 0.275 Hz and 32 Hz, when engaged the range is 27.5 Hz and 7.5 kHz.

3. Sweep through the different Mod Wave options and with the Blend button engaged the waveforms will morph from ramp to square and then triangle. With Blend disengaged the waves will change abruptly.

4. Keytracking can be enabled for either oscillator. Mod Fine and Osc Fine offer fine tuning control of the oscillators.

5. Timbre Out is the equivalent of Final Out on the 259. You can mix a variety of sound sources by adjusting the various other outs - Mod Out (Modulation Oscillator), Osc Out (Primary Oscillator), and Square Out.

6. Octave will adjust the Square Wave pitch.

7. Symmetry will blend between even and odd harmonics from the Primary Oscillator. Timbre will adjust the wave folding of the Timbre Out.

8. Experiment!

You are encouraged to add additional modulation sources to control the controls. This is the "programmable" part. You have near infinite freedom to explore the wealth of modulation opportunities which Bitwig has to offer.

I added a series of Average (slew) FX devices to smooth out the controller input MIDI signals from by BCF2000 (I dislike the hard transitions across 127 steps) so there is a ~250ms slew. You can adjust this to be higher or lower if you wish in the FX Grid. For me this increases the performative characteristics of this device and makes it more "natural" and "analog" feeling.

Is it the same as an actual Buchla 259 Complex Programmable Oscillator? No. I explored a lot available content to better understand what the original does and tried to emulate it faithfully (with the primary exception of the blended modulation option (thanks Oiko on the Bitwig Discord for this suggestion). Is it fun and does it make strange sounds? Yes! Maybe you'll enjoy it too - grab a copy from the link below.

AS 259 Complex Oscillator v1.5 (Bitwig v5.0+ fxGrid Preset) 

Warning: can produce frequencies and volumes which may damage hearing, audio gear and speaker coils. Be kind to your ears and gear.