COS Engineering - H1


” Our favourite headphone amplifier – paired with the Meze Empyrean headphones its an absolute joy

SKU COS_H1 Category

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COS Engineerings’ award winning H1 is a audiophile-grade DAC plus headphone amplifier . It is a half size component armed with the company’s proprietary algorithm.

For those who, like us, seek joy through headphones, the H1 should be high on your list.

The music presentation from the H1 is smooth yet dynamically powerful, and matched with high quality headphones such as the Meze Empyrean creates a simply wonderful listening experience.

The H1 has 4 powerful amplifiers to accommodate 2 unbalanced headphones or 1 balanced headphone.

An OLED screen, which displays input source, buffer, and volume, provides instant information.

The H1 can also be used as a DAC and pre amplifier (switchable) connecting to a power amplifier.

The built-in processing created by the COS algorithm is the secret behind the H1’s exceptionally good sound.


  • COS Algorithm and DSP:
    • COS Engineering’s proprietary algorithm up-samples original data to 176.4K or 192K, 24-bit by a process in an array of 4096 with 32-bit precision.
    • To rule out phase contamination that may stem from the more computationally efficient IIR filter, a linear phase delay FIR filter is chosen. This significant computation is handled by a powerful DSP capable of 3648 MMAC (millions multiply Accumulate Operations) per second.
  • Buffer & Re-clocking:
    • The H1 receives data from digital sources whether a streamer, a PC, a CD transport, or a mobile device, aligns them in exact frames with a one-second buffer (on/off option), and sends them out for interpretation by the COS algorithm.
    • The processed data is then converted to analogue signals, under the coordination of a crystal oscillator with a jitter precision less than 1ps and dedicated re-clocking circuitry.
  • Volume Control:
    • H1’s volume control is composed of a ladder with high precision resistors and an array of analogue switches which are low in resistance, noise and distortion.
    • No mechanical parts are used and frequent use does not erode its precision.
  • Power:
    • The H1 harnesses a selected switching mode power supplies with specially designed circuitry for lower noise.
    • In addition there is galvanic isolation between digital and analogue circuits
    • The power supply works with 100-240VAC so there is no need to select voltage.


  • DAC:
    • Digital input: USB x1 Asynchronous 1.0/2.0 (selectable); Toslink x1; SPDIF x1; AES/EBU x1.
    • Sampling rate: Optical/RCA/XLR up to 192K PCM 24 bit & DSD64 (DoP); USB 1.0 up to 96K PCM 24 bit; USB 2.0 up to 192K PCM 24 bit & DSD64/DSD128 (DoP)
    • Digital-to-Analogue converter: 24 bit DAC x1 (up to 192K 24 bit)
  • Volume:
    • Steps: 192 steps by 0.5dB/step
    • Total range: 96dB
    • Accuracy: within +/- 0.1dB
  • Headphone:
    • Supports 2 unbalanced headphones or 1 balanced headphone
    • Frequency response: + 0dB, – 0.5dB (20Hz – 20 KHz)
    • THD+N: <0.001% (-100dB) 192K, 24 bit, 20Hz – 20KHz, A weighted, 16 ohm load, 2V rms
    • Signal-to-Noise ratio: >110dB 192K, 24 bit, 20Hz – 20KHz, A weighted, 16 ohm load 2V rms
    • Full scale output: Unbalanced 6V rms; Balanced 12V rms
    • Output impedance: 16 ohm and up
  • Line out (selectable):
    • Frequency response: + 0dB, – 0.5dB (20Hz – 20 KHz)
    • THD+N: <0.001% (-100dB) 192K, 24 bit, 20Hz – 20KHz, A weighted
    • Signal-to-Noise ratio: >110dB 192K, 24 bit, 20Hz – 20KHz, A weighted
    • Full scale output: 2V rms
  • General:
    • Display: 128 x 64 pixels white OLED
    • Weight: 3.5 Kg
    • Dimensions (mm): 260 (W) x 250 (D) x 60 (H) not including footers
    • Power: 100-240 VAC
    • Normal operation: < 20W; standby 0.5W (typical)
    • Finish: silver or black anodised aluminium