Dutch A/D converter targets high-end recording and mastering

Grimm Audio, a newly formed collaboration between four of the Netherlands’ best known audio engineers, has launched an eight channel 1-bit A/D converter aimed squarely at the audiophile end of the market. Operating directly at 1 bit, 2.8224MHz, the AD1 | Grimm is eminently suitable for creating SACD masters from analogue sources.
In order to get past the limitations posed by commercially available converter chips, the AD1’s converters are made with discrete parts. The actual analogue signal path consists of only four resistors. This strategy pays off with unparallelled noise and distortion, while delivering data that can be directly pressed onto SACDs or processed in a DSD workstation.
Maximising the converter´s capability are a plethora of design techniques such as: an ultra-low noise clock source delivering the same precision irrespective of whether it is operated in locked or free-running mode; Low-Voltage Differential Signalling, eliminating jitter by ground-bound noise; EMC by design. From the very first planning stage onwards, parasitics were considered as an integral part of the circuit, not something to be worked around at the end of the development cycle; extensive use of wideband, quiet point-of-load shunt voltage regulators that effectively keep AC currents associated with the operation of analogue or digital circuits local, rendering interference between circuits zero; swinging-choke rectification, still the most effective and lowest-noise power-factor correction scheme known; audiophile construction details such as selected capacitor types, DC coupling and a copper-plated chassis.
The AD1 is constructed modularly and is available in two and eight channel versions, cascadable for an unlimited number of channels. The outputs are SDIF3 compatible. A companion box, the DD1, converts these signals into various PCM formats through nonaliasing, ripple-free decimation filters.
(GB)