The COS D1 (V2) DAC is a highly musical DAC that combines a preamp section with two inputs and a refined volume control, adjustable in 0.25 dB increments! $3,900, excluding fees and insured shipping via FedEx or UPS.
Here are some details...
The D1 is massively built (19 lbs). Protruding above the chassis is the volume wheel that has a particularly weighty, satisfying movement. Tiny LEDs display level below the volume wheel. The two combine to create a completely novel and iconic volume control that can also be adjusted from the beautifully executed hand remote.
COS Engineering paid special attention to the power supply to help the D1 achieve ultra low distortion figures (-14 below DAC spec). Inside, dual transformers are employed to keep analog and digital sections separated. For analog, the D1 has one RCA and one XLR input with matching outputs, so it can be used as a preamp. The whole device operates fully balanced for -114 dB noise. COS Engineering manually tunes the dual stereo DAC chips, running in mono to produce that balanced output.
These are some of the special features of COS Engineering's top model DAC/preamp.
- A proprietary algorithm with a linear-phase delay FIR filter up-samples data to 176.4K or 192K, processed by 3648 MMAC/sec DSP.
- Data storage in a 1 second buffer prior to conversion, featuring a crystal oscillator with jitter of less than 1ps and dedicated re-clocking circuitry.
- Dual toroid power transformers, one each for the digital circuit and the analog circuit to avoid possible interference.
- Individual DAC circuit boards with high performance DAC chips, manually tuned and matched, running mono for each channel.
- Volume control utilizing laddered high precision resistors and an array of analog switches, which are low in resistance, noise and distortion.
Manufacturer Specs:Preamp:
Analog Input: Balanced x 1, Unbalanced x 1
Analog Output: Balanced x 1, Unbalanced x 1
Residual Noise: less than 2uV (-114dBV) / 20Hz~20KHz non-weighted, input terminated
Input Overload: 16V (balanced), 8V (unbalanced) / THD less than 1%
Input Impedance: 100K ohm
Output Impedance: 200 ohm (balanced), 100 ohm (unbalanced)
Maximum Output: 16V (balanced), 8V (unbalanced) / THD less than 1%
Voltage Gain: 0dB
Volume: 256 steps by 0.25dB/step, total range: 64dB / less than ± 0.1dB accuracy
DAC:
Digital Inputs: USB 1.0/2.0; RCA S/PDIF x 2; TosLink x 2
Sampling Rate: up to 384 kHz, 24-bit or 128 DSD (via USB)
Full Scale Output: 2V (unbalanced), 4V (balanced)
Signal To Noise Ratio: greater than 110dB
Digital-to-Analog Converter: 24-bit DAC x 2 / up to 192Ksps, 24-bit
Digital Filter: COS Proprietary; Linear Phase Delay
General:
Weight: 19 lbs (8.6kg)
Dimensions: 16.3 in (W) x 11 in (D) x 3.9 in (H) / 40 cm (W) x 30 cm (D) x 10 cm (H)
Power: Normal Operation less than 50W; Standby less than 5W
Universally positive reviews:https://www.hifiplus.com/articles/cos-d1-digital-converterpreamplifier/https://6moons.com/audioreviews2/cos/1.htmlhttp://hifiknights.com/reviews/sources/cos-engineering-d1/Note to buyers:PP fee and shipping are extra. However, the friendly buyer receives my offer to share over 30 years of system building experience and hard earned knowledge to help maximize their purchase, including access to component insights, system tips, and recommended tweaks. Overall my experience with the COS D1 DAC, in my various systems, is as a device that puts music over specs (though no slouch there), offers a particularly unique ergonomic character, and makes a solid foundation upon which to build yourself an extraordinary sounding system. It certainly deserves a good home.
