The unit consists of oscillator which generates SAW & SQUARE WAVE using 16-bit band-limited wavetables, thus making the number of harmonics limited. After that, the signal itself goes through a simple implementation of MOOG filter, whose frequency range is chosen by MIDI commands and which is affected by the level of the envelope. The filtered signal then comes to the controlled amplifier, which creates the signal shape, and in the end through DAC (WM8762) and pre-amp circuit goes to the audio jack 6.35mm.
Right channel – drums and other things, left channel – BassBoys…
Midi: Children – Robert Miles (rearranged)
The BassBoy is $29 at the Analog Digital World site.