Sapphire DAP-800

The Sugden Sapphire DAP-800 is a high-end digital pre-amplifier and DAC, designed and manufactured by Sugden employees at the company’s premises in West Yorkshire. Its development combines musical performance with a practical user interface, pride of possession and product longevity, while accommodating current digital technologies.

The DAP-800 is an analogue pre-amplifier with a separate built-in DAC facility. The analogue and digital sections are self-contained stages, each with its own power supply, voltage regulation and circuit board assemblies. The analogue stage uses a 50 watt toroidal transformer, while the digital stage has a 15 watt E-core transformer. The digital power supplies are totally isolated from the analogue stage.

Sugden’s use of through-hole components instead of surface-mount components, where possible, is intended to support product life, performance and reliability. The analogue pre-amplifier section uses the Sugden VCV circuit in its most developed form. This incorporates a high-impedance input section and a current-gain stage without attenuation problems, driving a folded-cascode stage into a Class ‘A’ output stage. The folded-cascode circuit provides wide bandwidth, maximum dynamics and low capacitive connectivity.

The tonal balance remains consistent irrespective of output level, with a sense of headroom, imaging and soundstage. The analogue output stage also includes post-conversion filtering for the DAC.

The DAC section accepts USB, optical and coaxial S/PDIF signals. It uses a non-oversampling, digital-filtering-free configuration, with a Wolfson Microelectronics device serving as the digital interface transceiver. The received USB signal passes through a circuit incorporating a Texas Instruments Universal IC, whose S/PDIF output is then re-clocked and de-jittered by the Wolfson interface transceiver.

Sugden adopted this digital processing configuration after many hours of auditioning a wide sample of DSPs. The company’s preference is based on auditory perception and musical performance, particularly dynamic balance, tonal balance, voice and emotion. The Sapphire DAP-800 presents the analogue and digital functions as separate, independently powered sections within one pre-amplifier.