A real-time acoustic violin emulator for electric violins

Patrick Gaydecki

A stand-alone electronic device has been developed that processes the raw electrical output produced by an electric violin, generating an output signal which, when fed to an amplifier, produces a sound that approximates closely the timbre of an acoustic or wooden instrument. The system comprises a high-impedance preamplifier, a 24-bit sigma delta codec and a digital signal processor (DSP) operating at 600 million multiplications-accumulations per second (MMACs). The device holds in its memory the far-field impulse response of a wooden instrument; this is convolved in real-time with the input signal to produce the modified output signal. The unprocessed output produced by an electric violin is typically a saw-tooth waveform, which results from the slip-stick regime created under normal bowing. Similarly, such a waveform is also manifest on the bridge of acoustic violins and for this reason the system may also be used with wooden instruments fitted with pickups mounted on the bridge. The device incorporates a standard line-output for connection to audio amplifiers and an additional headphone driver for silent practice. Additional features include adjustable gain, a parametric equalizer and a facility that enables the user to download and store additional impulse responses in non-volatile memory.

Mots clés: violin impulse response; real-time emulation; DSP; violin body

Domaines: Acoustique [physics.class-ph]

Patrick Gaydecki. A real-time acoustic violin emulator for electric violins. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810691⟩