Home COS Engineering D10 V2 preamplifier/dac – COSplay

COS Engineering D10 V2 preamplifier/dac – COSplay



  • Appearance
  • Playback
  • Modular
  • User-friendly


  • None we can think of

Price: € 5990

Build quality
Alpha-Audio Approved
COS D10 V2 pre-amp streamer


Today we are in Taiwan, an island east of China, praised for its innovation and know-how. A country that bets hard on knowledge and entrepreneurship. The young company COS Engineering is a prime example of that philosophy. It is an innovative company that puts lots of technology in their products. We’re looking at the COS D10 V2. 

Cos Engineering was founded, like so many companies, by three friends who share a passion for (digital) audio. They only have five devices in their portfolio, but they are all technological marvels. Today we look at their all-in-one device. The COS Engineering D10 V2 (delivered by Hexagon Audio). In its basic form a preamplifier, dac and headphone amplifier. But the the full-option version we received, a device that does virtually everything except make coffee. Let’s check it out!

We’ll get right to the point. The COS D10 V2 looks amazing! It is truly a “thing of beauty”. We have rarely seen such a beautiful device. It exudes class and luxury at the same time and holds it’s own against any high-end device. We got the black version but think the silver one looks even better. The seamless lines, the edges, the matte finish, the logo… Everything looks perfect. Is that important? Off course it is.

In addition to a volume knob, the sleek front contains an OLED screen with no less than three headphone jacks next to it. The screen shows the volume and the selected input. You can dim the screen but not turn it off completely. The chassis itself consists of a reinforced internal part and an outer shell made of aluminum. Clearly, COS hasn’t skimped on the finish. The COS D10 V2 comes in a flightcase and fully deserves it. Why don’t more manufacturers do that?

A device in this price range should not only look good, it should also work intuitively and smoothly. We can be very brief about the COS D10 V2: everything functions without glitches and without fuss. This device is “fool proof”. You don’t have to be an ICT expert to get the thing working. Moreover, after a few minutes music is playing through our speakers. That’s what you’d expect at this level. The stylish remote control is included in the package.

Burrrrr Brown

A lot of attention has been paid to the preamplifier. With every turn of the volume knob you can hear the relays clicking rhythmically. Volume adjustment is very precise because you can work with small steps of 0.5 dB. You can use XLR or RCA to connect a pair of active speakers or you can connect the COS D10 V2 to a power-amp. It als has XLR and RCA inputs. In any case, the preamp is very transparent but let’s not get ahead of ourselves.

First some more info about the built-in dac. The heart of the dac are Burr Brown PCM1792 dac chips, two per channel. COS applies its own algorithm to them by means of an FIR filter. Then the dac buffers everything before converting the signal to analog. This converter has every connection you can think of. Optical, coax, aes/ebu, bnc and i2s. Nice!

The analog and digital parts each get separate power supplies to minimize interference. The versatile headphone amplifier must not be forgotten. It has three outputs, two normal outputs and one balanced 5 PIN jack. This headphone amplifier can drive both sensitive and less sensitive headphones and is the final piece of this extraordinary triptych.


But there’s more. You can add a streaming module (RoonReady) and/or a phono stage. You can do this at purchase or afterwards. Both the streaming module and phonostage cost 1190 euros each. Via the streaming module, you get access to Tidal, Qobuz, Deezer and Spotify. You can either stream via an ethernet cable or wirelessly over the your wifi-network. And for enthusiasts: MQA is fully supported (full unfold).

The MM/MC phonostage is also very versatile, providing 5 resistance values and three capacitance values. Via DIP switches, you can easily set the ideal gain for your element. Since we do not have a turntable in the system at the moment, the phonostage has not been tested.

Version 2

In 2022 a number of changes were made to the original design, hence the V2 in the name. We briefly give you the most important ones. In the dac a new oscillator was implemented which should ensure even less jitter. In the streaming module jitter has also been reduced by implementing a new low jitter TCXO clock. The analog section got a new transformer installed and the whole unit also got better wiring.

Type test
Single Test
  • Streamer ethernet
  • Streamer wifi
  • Analog RCA
  • Analog XLR
Product type
Max samplingrate
192 kHz
Max bit depth
24 bit
    Amplifier type
    Amplifier technology
    Class A
    Amplifier inputs
    • Analog RCA
    • Analog XLR
    • Analog Phono MM
    • Analog Phono MC
    • Digital Coaxial
    • Digital Optical
    • Digital BNC
    • Digital USB
    • Digital AES
    • HDMI (Audio)
    • Streamer Ethernet
    • Streamer wifi
    Amplifier outputs
    • Analog RCA
    • Analog XLR
    • Width: 41,5 cm
    • Depth: 28 cm
    • Height: 10 cm
    Weight amplifier
    10 Kg
    Build in dac