ЦАПы — Extraudio DAC2 QUAD R-2R Ladder

Extraudio builds the DAC2 converter on a proprietary R-2R ladder topology in a quad arrangement. More than 600 Vishay foil resistors with 0.01 percent tolerance are soldered by hand in the Netherlands to form the ladders, giving a 32-bit ladder depth. Three independent FPGAs act as the digital engines, each programmed for its own set of tasks.

Key specs that matter

Frequency response is flat within 0 dB from 5 Hz to 750 kHz. Signal-to-noise ratio exceeds 132 dB over a 20 kHz bandwidth, THD at -1 dB stays below 0.004 percent, resistor precision is 28 bit at 0.01 percent, and typical clock jitter is 0.3 ps RMS. S/PDIF accepts up to 24-bit/192 kHz, USB and I2S up to 24-bit/384 or 768 kHz, and DSD arrives as DoP at DSD64, DSD128 or DSD256. The chassis is 44 cm wide, 12 cm high and 40 cm deep and weighs 16 kg, or 18 kg when packed.

Engineering and use context

Eight digital inputs, each galvanically isolated, are chosen with a rotary selector offering ten bit position combinations, and they include I2S over RJ-45 or HDMI LVDS as well as Bluetooth 5.0 with aptX HD. Two output paths are provided. The direct R-2R output leaves the ladder without a buffer, delivering 2.3 V on RCA at 50 ohm and 4.6 V on XLR at 3 ohm. A second, Class A buffered output raises the level to at least 6 V on RCA and at least 12 V on XLR at the same impedances. Extraudio lists programmable audio oscillators for clocking, a modular layout, EMI and RF filtering on the mains input, dual and quad power supplies and a separate USB 2.0 power module among its in-house technologies. The case is machined from 6000-series aircraft-grade aluminium. Mains input can be 115 V or 230 V at 50 or 60 Hz, with 50 W drawn in operation and under 0.5 W in standby. Handheld remote operation is offered as an extra-cost accessory.

Pairing

The high-level buffered output makes it possible to drive a power amplifier directly and control volume elsewhere in the chain, while the direct output suits a conventional line input on an integrated amplifier. Streamers with I2S over HDMI or RJ-45 can connect without passing through S/PDIF or USB.

Alternatives

The Extraudio DAC1 MKII is a smaller converter in the Extraudio range built around a dual R-2R ladder in place of the quad layout.