303tracker is a sequencer application to calculate and play TB-303 like bassline loops to create for example acid, techno triphop or anything. You can use 303tracker as a render-program to create bassline loops and use them in music-sequencers like Octamed Soundstudio.

I developed the sequencer at a time that I couldn’t afford a real Roland TB-303 synthesizer.

303tracker has a very easy graphical user interface which lets the user create a track in several ways. Samples can be saved in 8 bit and 16 bit format IFF-8SVX and AIFF in 22.05 kHz to 44.1 kHz or can be dumped via Midi Sample Dump to your 16bit external MIDI sampler.

Some pictures of the interface:

The 303tracker main editor screen. Based on the popular “tracker” style editor, the sequence is top-down. For every, filter frequency, resonance and other essential 303 tweakables, a separate column lets you control its value.


The 303tracker main editor screen with the basic 3-channel mixer window.


Advanced settings of the 3 stages of the sound: the VCO (oscillator), the VCF (filter) and VCA (amplifier).


The “classic bassline” screen as an alternative interface to the default tracker approach… for those who prefer to program bassline like on a real TB-303.


The drum machine screen – the sound engine was roughly based on the TR-909, while the interface is styled somewhere between a TR-808 and a Pearl Syncussion.


Wacky Filter Factory: a separate module which allowed you to add filter sweeps over the entire bassline sound sequence.


This is how the installation process looked. 


And finally the original logo.


Prior to 303tracker, I developed other programs. Here’s an example:

Later on, I coded a PHP / Javascript lite version of 303tracker. called 303online: