D/A Converter Soulution 560 D/A Converter

Soulution 560 – D/A converter with Zero-Phase-Technology and digital volume control

The Soulution 560 D/A converter is a reference digital-to-analogue converter built on engineering solutions taken from the 745 SACD player. It combines high-quality digital input interfaces, an ultra-precise master clock generator that suppresses jitter, intelligent digital signal processing with oversampling and analogue output stages on the level of a top-tier preamplifier. The integrated digital volume control ranging from 0 to –79 dB in 1 dB steps allows a power amplifier to be connected directly, with no preamplifier in the signal path.

The design is based on a consistent dual-mono layout of the output stages and separate power supplies for the digital electronics and the analogue section, which reduces mutual interaction between the circuits. The audio data is buffered and then upsampled to 24 bit/384 kHz using an Anagram Technologies interpolation algorithm. The conversion itself is handled by Burr-Brown converters in a digitally balanced configuration, with their internal upsampling and filter stages left unused. DSD signals are converted to PCM before the final conversion, which the manufacturer considers the more accurate route.

The output currents of the converters are turned into voltage in a conversion stage with a bandwidth of 40 MHz, contributing to an exceptional signal-to-noise ratio (> 140 dB) and high dynamics in the analogue domain. This is followed by a wideband output stage with a bandwidth of 20 MHz (–3 dB), whose response speed shows in the legibility of fine detail and in the spatial rendering of the soundstage. THD+N distortion remains below 0.002 % and channel separation exceeds 130 dB, supporting stable localisation of instruments.

The key element is the proprietary Zero-Phase-Technology, which eliminates the small timing errors arising in the analogue low-pass filter. A 3rd-order Bessel filter with a 120 kHz cut-off frequency shows a phase shift of up to 15° within the audio band; thanks to the correction, the phase error of the music signal stays below 1° across the 20 Hz – 100 kHz range. The result is a more realistic, three-dimensional presentation with more air around instruments and voices. The converter offers AES/EBU, SPDIF-RCA, optical, USB and network inputs (up to 24 bit/384 kHz and 1 bit/5.64 MHz via USB and network), XLR as well as RCA outputs, and control via buttons and a rotary knob on the front panel.

Key features

• Zero-Phase-Technology: Phase error below 1° across 20 Hz – 100 kHz
• Upsampling: Anagram Technologies interpolation to 24 bit/384 kHz
• Conversion: Burr-Brown in a digitally balanced configuration
• Design: Dual-mono outputs and separate power supplies
• Connectivity: AES/EBU, SPDIF, optical, USB and network input
• Volume: Digital control from 0 to –79 dB in 1 dB steps