Metrum Acoustics ONYX DAC

The designers at Metrum Acoustics developed the new Onyx DAC with the goal of creating a product that combines affordability with outstanding sound quality.

This was an unprecedented challenge, centered around a completely new conversion chip, the DAC3, developed exclusively by Metrum Acoustics and first introduced in the Pavane model.

The R2R ladder networks employed in each of the four DAC modules—two per channel—together with the FPGA correction module, deliver superior performance. The FPGA module splits the audio samples into two separate data streams, one for each channel. Each of the two DAC modules assigned to a single channel processes a portion of the data within the most linear operating range of the DAC chip. This approach achieves exceptionally high linearity, down to -145 dB, allowing the Onyx to attain an effective 24-bit resolution.

Thanks to its dual-mono circuit design, the Onyx achieves extremely high channel separation of 120 dB across the entire frequency range. This enables excellent soundstage reconstruction with precise placement of instruments within the virtual acoustic space.

In summary, the Onyx is a DAC that incorporates all the experience accumulated by Metrum Acoustics' designers over the years, combining it into a high-end converter that performs effortlessly in any audio system. The Onyx offers remarkably natural sound reproduction, employs NOS (Non-Oversampling) technology, and at the same time embodies all the technological advances developed in recent years.

The sonic performance of the Onyx is even more engaging because it reveals the finest details contained in a recording without ever becoming fatiguing. In terms of sound quality, the Onyx can be considered among the finest playback systems available today, as it represents the synthesis of all the positive characteristics found in Metrum Acoustics’ flagship models, the Pavane and the Adagio.

A note regarding discrete R2R ladders and why they cannot achieve the performance obtainable with Metrum DAC3 modules:

1. Their accuracy cannot exceed 0.01%; therefore, by design, their resolution cannot be greater than 14 bits.

2. Temperature variations across the circuit board lead to linearity issues.

3. High sensitivity to electromagnetic interference and humidity.

For these reasons, Metrum uses only laser-trimmed ladder networks to achieve perfect linearity and a dynamic range of 145 dB. In addition, the components are carefully encapsulated to prevent temperature fluctuations and electromagnetic interference.

Technical Specifications

• Operating Principle: Non-Oversampling (NOS) DAC. Forward Correction Technology. Transient DAC 3 Modules – 2 per channel

• Power Supply: 15 VA toroidal transformer

• Mains Voltage: 220/230 V AC, 50/60 Hz

• Inputs: 1 × Optical, 1 × Coaxial, 1 × AES/EBU, 1 × USB or 1 × I²S

• Outputs: One pair of single-ended RCA stereo outputs (2 V RMS); one pair of balanced XLR outputs

• Frequency Response:

  • 1 Hz – 20 kHz (-1 dB) at 44.1 kHz sampling rate

  • 1 Hz – 65 kHz (-1 dB) at 192 kHz sampling rate

• Distortion: 0.006% THD

• Noise: -145 dB at 2 V RMS

• Output Impedance:

  • RCA: 100 Ohms

  • XLR: 100 Ohms

• Supported Sampling Rates:

  • Optical: 44.1 – 96 kHz

  • Coaxial and AES/EBU: 44.1 – 192 kHz

  • USB: 44.1 – 384 kHz

• Output Voltage:

  • RCA: Max. 2 V RMS

  • XLR: Max. 4 V RMS

• Dimensions: 290 × 250 × 60 mm

• Weight: 3.1 kg