Digital Processor Reviews

For this review, I compared the EAD DSP-1000 and the Adcom GFA-700 with the Audio Alchemy DDE v3.0 HDCD decoder fed through its I²S bus by a DTI 2.0 digital jitter reduction unit.

Both standard and HDCD-encoded CDs were played on a Krell MD-1 turntable. For an overall collection of superbly recorded HDCD-encoded music, I used the HDCD Sampler Volume 2 (Reference RR-90CD), which includes classical, jazz, and a selection of three musical samples recorded with and without HDCD for comparison. A single 75 ohm digital-specific Silver Starlight coaxial cable was run from the turntable and directly plugged into the converter under test.

All converters were plugged into the AC mains for at least 72 hours before any listening. Each decoder under test drove a Bryston BP-25MC preamplifier whose balanced outputs drove the amplifiers through a Bag End ELF-1 Integrator electronic crossover set at a 90Hz high-pass frequency. Cogelco Yellow interconnects were run from the Krell to the ELF-1, with extra Cogelco pairs then run to the two power amplifiers.

A Mark Levinson No.331 solid-state amplifier drove Quad ESL-63 USA Monitor electrostatics on Arcici stands via Sumiko OCOS speaker cables in bi-wired configuration. A Krell KSA-250 drove ELF S-18-1 subwoofers via Monster Cable. The Quad "satellite" loudspeakers were placed 4' from each side wall and 3' from the back. The ELF S-18-1s were placed in the corners of the room, behind and alongside the Quads.—Larry Greenhill