Massdrop Airist R2R Ladder DAC

I have owned this since I purchased it on Massdrop/Drop back in 2019. I moved to an Amp/DAC combo and no longer need it.

The R-2R DAC contains two PCB boards: the bottom board with power, USB, and different file-conversion technologies, and the top board with the resistor ladders, designed to have the shortest distance between parts for the cleanest results. The hardware includes a custom programmable logic device and augmented power regulation with voltage-stabilization circuits. There is a buffer/isolator stage to each bit on the R-2R ladders, while the output buffer stage boasts five op-amps per channel. Finally, the inputs, outputs, and USB/SPDIF conversion are all located on a separate PCB from the resistor ladders.

These are hard to find and Massdrop/Drop is not bringing them back as Airist Audio no longer exists.

SPECS

• Ladder width: 24 bits
• Decoding format: Sign-magnitude
• PCM formats: Up to 24 bit/384 kHz over USB or 24/192 over coaxial/optical
• DSD formats: DSD64/128 over USB and S/PDIF if native DSD stream, DSD64/128 over USB using DoP, DSD64 over S/PDIF for DoP
• DSD method: Converted to PCM
• Filters: Linear-phase FIR
• Galvanic isolation: Yes
• Clocks: Low phase-noise NDK
• Frequency response, 20 Hz–20 kHz: +/-0.1 dB
• THD+N at 1 kHz: 0.08%
• SNR: 118 dB
• Crosstalk at 1 kHz : -120 dB
• Maximum output:  2.5 VRMS
• USB controller: XMOS XU208
• Inputs: USB, coaxial, optical
• Output: RCA
• Dimensions, L x W x H: 8.1 x 8.1 x 1.2 in (207 x 206 x 30 mm)
• Length with buttons and RCA port: 8.7 in (220 mm)
• Height with feet: 1.5 in (39 mm)
• Weight: 48.2 oz (1,366 g)