Arcam Delta Black Box (1987)

An outboard D/A converter from Arcam's Delta series, released in 1987 with a discrete analog stage and custom digital circuitry.

Overview

The Arcam Delta Black Box is an outboard D/A converter and digital audio processor introduced in 1987 as part of Arcam's Delta series of hi-fi separates. Arcam (formerly A&R Cambridge) built it, and it was among the early commercial standalone DACs. It takes optical and coaxial digital inputs, runs 16-bit with 4x oversampling, and handles sampling frequencies of 44.1 kHz and 48 kHz.

Specifications

Design

The Delta Black Box uses an Arcam custom IC and a specially selected Philips D/A converter IC. The analog filter is fully discrete. The audio stage is a direct-coupled, discrete design running in Class A with no op-amps in the signal path - the only visible op-amps serve the DC servo circuit for offset control. The D/A converter board sits on a sorbothane vibration damper, and the whole case is aluminum. The power supply has an independent transformer and seven independent regulators for the analog and digital circuits, plus a star earth system to keep noise down. Reviews noted a slightly bright tonal character, described as "hot on the top end."

Context

The Delta Black Box came out in 1987 as part of Arcam's Delta series, a line of high-fidelity separates developed during the 1980s. Arcam claims to have produced the first commercial outboard D/A processor. Stereophile reviewed it, among other publications, and it was compared to contemporaries such as the Musical Fidelity Digilog. It stayed in enthusiast use well beyond its release.

eBay Listings

Arcam Delta Black Box 50 Dac. Immaculate condition

$214

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