ATC, better known for its studio and domestic hi-fi loudspeakers, has added two new electronic components to its stables – the CD2 CD player and SIA2-100 stereo integrated amp/DAC, both obviously made for each other and designed to drive high-quality passive speakers.
The CD2 uses the rugged TEAC 5020A-AT transport, while its AKM-driven DAC stage operates in conjunction with an output filter stage comprising a digital filter and ATC’s own low-noise multiple feedback analogue filter. Four gain stages, each comprising 11 discrete components, provide a “true” differential output for both channels.
“The output stages are configured as unity gain complementary compound (Sziklai) pairs, biased in class A. The positive and negative drivers are arranged in parallel to ensure that signal delays and phase shifts on each side are similar,” says ATC.
The CD2 has line-level RCA and “true differential” XLR outputs. Also on board are optical and coaxial digital outputs.
“Enormous care has been invested in reducing distortion and noise throughout. ATC’s preference for distributed ‘local’ power regulation and decoupling means that no fewer than nine individually calibrated power regulators are deployed in the circuit design. The digital coax output uses a high performance isolation transformer to prevent possible hum loops if both audio and digital signals are connected to the same equipment. All PCB track lengths are as short as possible, and grounding and screening is meticulously applied.”
The SIA2-100 “a versatile one-box design for D/A conversion and pre/power amplification duties specified to generate 100 per channel (continuous into eight ohms).”
It has two pairs of RCA line inputs, a front-panel mounted 3.5mm jack input, optical and coaxial digital inputs, and a USB input on a USB B socket. There is a single pair of stereo power amplifier outputs, a stereo line-level output on RCA phono sockets, and a front panel mounted headphone output on a 6.35mm jack socket.The headphone amplifier is biased in class A and is specified to drive a range of headphones from 32 to 600 ohms.
“Rigorous measures are taken to reduce noise and distortion in the SIA2-100. Its power amplifiers use the circuit topology which has been revised and refined over the past 30 years for all ATC power amplifiers. Lateral Mosfets are deployed in a common source configuration to provide very low distortion together with a wide frequency response. A peak limiter is included to protect the loudspeaker drivers in the event of an overdrive. To reduce intermodulation and cross-talk aberrations there are separate power supplies for the pre-amplifier and power amplifier sections.
“ATC’s discrete analogue design and use of multiple local power supply regulators provides the optimum operational platform for the SIA2-100’s AKM onboard DAC and USB receiver. The USB input will handle PCM sample rates from 44.1 kHz to 384 kHz, with word lengths to 32 bits, and also decode DSD sources at 2.822 MHz (single rate, DSD64), 5.644 MHz (double rate, DSD128). All inputs, analogue and digital, achieve distortion figures below 0.001%.”
The chassis for both components are constructed to be heavy, rigid and well-damped with precision-machined 12mm aluminium front panels finished in brushed and anodised “titanium” silver.
Both units will be available in April, retailing at £1,500 for the CD2 and £2,500 for SIA2-100.