BassBoy is a monophonic digital MIDI-controlled bass synthesizer. With BassBoy, your MIDI music will sound like a real live stage band. Powerful 16-bit DSP signal processing and high-performance DAC ensure that you will enjoy each and every sound.
The unit consists of an oscillator which generates sawtooth and square waveforms using 16-bit band-limited wavetables, thus making the number of harmonics limited. After that, the signal itself goes through a simple implementation of a 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 a DAC (WM8762) and pre-amp circuit that goes to the 6.35mm audio jack.
Note that a MIDI DIN connector is not included. MIDI input is via a two-pin header (to which you can wire a MIDI DIN connector's pins 4 and 5).
The BassBoy runs on an ATxmega32D4 microcontroller. The firmware was written in straight assembly, ensuring efficient operation. Sampling frequency is 31.25 kHz, which generates audio in the range up to 15.625 kHz. Although it's based on an 8-bit processor, the signal processing inside the unit is 16-bit.
View a video of BassBoy in action.
Download the BassBoy user manual for details on usage and effects.
- Power supply: +10V to +13V DC max.
- Current consumption: 100mA max.
- MIDI input isolated by opto-coupler.
- Maximum output voltage: Approx. 2.2VRMS = 6.2V peak-to-peak output impedance 1MΩ; approx. 1.95VRMS = 5.5V peak-to-peak output impedance 10kΩ (measured on the 6.35mm jack with generated sine wave directly toward DAC). Output impedance >10kΩ.
- Plays notes in range of 32.70 Hz to 523.25 Hz, i.e. MIDI notes 24 through 72 (C1-C5). Maximum deviation ±1.5 cents.