ЦАПы — Extraudio DAC1 MKII DUAL R2R

The DAC1 MKII Dual R2R is a stereo converter made by Extraudio, a European maker of amplifiers and sources that assembles its products by hand. As the name says, it uses two discrete resistor ladder converters instead of an off the shelf delta sigma chip, and it follows a minimal front panel approach with LED indicators and no display.

Key specs that matter

The R-2R ladder topology runs at 32 bit depth, with 600 Vishay foil resistors of 0.01 percent tolerance giving 28 bit precision. Extraudio quotes THD below 0.004 percent at -1 dB, noise sitting more than 132 dB below signal in a 20 kHz bandwidth and a frequency response flat within 0.1 dB from 5 Hz to 180 kHz. Clock jitter is 0.3 ps rms typical. The RCA output delivers 2.3 V from 50 ohm, and the balanced XLR output gives 4.6 V from 3 ohm. The chassis is 44 cm wide, 12 cm high and 40 cm deep and weighs 10 kg.

Engineering and use context

Eight galvanically isolated digital inputs are available. As standard there is one RCA and one BNC S/PDIF, one XLR AES/EBU, one optical and an isolated USB 2.0 type B. An optional I2S module adds RJ-45 or HDMI LVDS connections with its own rotary selector, and a Bluetooth 5.0 receiver with aptX HD and LDAC can also be fitted. S/PDIF accepts up to 24 bit and 192 kHz, USB and I2S go up to 24 bit and 384 kHz, and DSD64, DSD128 and DSD256 are carried over DoP. Two medical grade transformers wound in the Netherlands feed four separate supplies, with a 45,000 uF capacitor bank and 14 fast recovery Schottky diodes, and the rails keep digital and analogue sections apart in a dual mono layout. The case combines 6000 series aluminium with steel around a gold plated four layer board. Mains input is 115 or 230 V, draw is 50 W and standby is 0.5 W. Warranty cover is three years. Shipping weight is 11.1 kg. Every input is selected from the front panel, where LED indicators replace a display.

Pairing

Its low balanced source impedance lets the converter drive long XLR runs into a preamplifier or integrated amplifier without trouble. The X251 MKII integrated from the same maker uses a chassis of identical width, height and depth for a matching stack. The optional Bluetooth receiver lets phones and tablets stream to the converter wirelessly, and the I2S module accepts signals from compatible streaming transports.

Alternatives

The Extraudio DAC2 Quad R2R uses four ladder converters instead of two for buyers wanting the brand's larger R2R design.