D/A Converter Audiobyte SuperVox Matt Silver

Audiobyte SuperVOX — multibit DSD converter with a proprietary multi-level delta-sigma architecture

SuperVOX is a fully balanced D/A converter built around a proprietary multi-level delta-sigma architecture, developed after years of experimenting with virtually every available method of conversion. Instead of off-the-shelf DAC chips, the work is done by an AMD Artix 7-series FPGA — the most powerful device Audiobyte has ever used in its products — complemented by a dual cluster of high-speed switches and proprietary code defining the behaviour of the hardware. The emphasis on short, precise signal paths forms the foundation of the whole unit's sonic character.

The modulator runs at a sampling rate of 11.28/12.28 MHz, fifth order, 36-bit precision and 33 levels. The conversion stage uses arrays of equally weighted elements that outwardly resemble a ladder architecture, yet work differently — paired with dual-loop element error compensation combining noise shaping with the selection of minimum-activity patterns. The goal is Intersymbol Interference Mitigation, i.e. suppressing the distortion that arises during reconstruction filtering when previous samples influence the following ones.

Timing is handled by the advanced Femtovox clock manager inherited from the higher product lines, which reduces jitter and stabilises the spatial image. The output is managed by a discrete output stage with a maximum amplitude of 2.9 V RMS, DNR of 120 dB and THD of 110 dB at 0 dB. Lowering the noise floor without aggressive filtering helps preserve natural dynamics, the legibility of decays and precise instrument localisation. Three upsampling filters are available (minimum, hybrid, linear) along with a bypassable digital volume control with 256 steps of 0.5 dB, allowing a power amplifier to be connected directly.

Power comes from a low-noise linear power supply, while internal wiring uses silver-plated copper conductor. The input section comprises USB, I2S (LVDS over HDMI) and SPDIF, with XLR and RCA outputs. The entire unit is housed in a chassis milled from a solid block of aluminium, bead-blasted and anodised, measuring 310×290×64 mm and weighing 3.8 kg.

Key features

• FPGA conversion: AMD Artix 7-series with proprietary hardware code
• Delta-sigma modulator: 33 levels, fifth order, 36-bit precision
• Femtovox clock manager: Precise timing and jitter-free playback
• Discrete output stage: Fully balanced topology, XLR and RCA
• Linear power supply: Low-noise supply and silver-plated internal wiring