BDX-909: TR-909 Bass Drum Plugin by Rave Generation

The core of BDX-909 is a model of the TR-909 bass drum. Rave Generation says the design uses diode clipping, transistor VCA modeling and RC envelope circuits to reproduce the kick and its nonlinear behavior.

The noise layer is based on a linear-feedback shift register running at a 300 kHz clock rate, which the developer uses to shape the analog noise in the attack transient. A phase-aware click stage adds to the initial impact of each hit.

The clipping amount can be automated from the modulation wheel (CC1). Lower positions stay close to the classic asymmetric clipping of the 909, the middle range blends smoothly, and the top of the range pushes into heavy, asymmetric distortion.

BDX-909 has two MIDI modes. In standard mode every key triggers the default kick tuning, while notes C6 to B7 select one of 24 preset tunings, each with its own base frequency. Chromatic mode maps the full keyboard to pitch, so kicks can be played as melodic bass sounds.

Tune X2 doubles the pitch envelope decay time and Decay X2 doubles the amplitude decay time, which extends the range for longer or more sustained tones. Velocity response is divided into four zones, and pitch bend covers a standard range of plus or minus 12 semitones.