ONIX Beta XI2 Portable DAC Headphone Amplifier

A Tube Dongle DAC from ONIX

The ONIX Beta XI2 is a high-end USB dongle DAC and headphone amplifier built around a genuine tube output stage. It takes the vacuum-tube character ONIX is known for and shrinks it into something that plugs straight into a phone or laptop, measuring just 69.8 × 39 × 14mm and 45.3g. A pair of JAN6418 tubes sits behind a window on the front panel, so you can watch them glow while you listen, and you can switch between tube and pure transistor output at any time.

Dual Cirrus Logic CS43198 DACs

Conversion uses two Cirrus Logic CS43198 converters, one per channel, a flagship pairing that appears in far larger and more expensive players. Resolution reaches 768kHz / 32-bit and DSD512, and the USB connection supports both UAC 1.0 and UAC 2.0 so the XI2 works with legacy hardware as well as current devices. The analogue stage follows with a pair of OPA1662 operational amplifiers and four BUF434A buffers, giving the output both the current and the control that small dongles usually lack.

Tube and Transistor Modes with Real Power

The XI2 gives you a choice no ordinary dongle offers. In transistor mode the 4.4mm balanced output delivers 180mW @ 32Ω in low gain and 550mW @ 32Ω in high gain, with distortion of just 0.0008% and a 128dB signal-to-noise ratio. Switch to tube mode and the balanced output still delivers 550mW @ 32Ω in high gain, now with 0.06% distortion and a 127dB signal-to-noise ratio — the harmonic profile changes, the drive does not.

Single-Ended Output for Sensitive IEMs

The 3.5mm single-ended output covers the other end of the headphone spectrum. In transistor mode it produces 45mW @ 32Ω in low gain and 180mW @ 32Ω in high gain with 0.0006% distortion, 124dB signal-to-noise ratio and 0.3Ω output impedance, which keeps sensitive in-ear monitors quiet. Tube mode runs 37mW and 152mW @ 32Ω with 0.06% distortion. Both outputs share a 20Hz–40kHz frequency response.

Precision by ONIX: Screen, Buttons and LED

A 0.87-inch screen shows track information and lets you change settings without reaching for a phone, while hardware buttons give you quick volume changes and playback control by feel. A multicolour LED acts as a sampling-rate indicator: blue for PCM up to 48kHz, green to 96kHz, yellow to 192kHz, purple for the highest PCM rates, and white for DSD. Gain, digital filters and screen orientation are all directly accessible on the unit.

ONIX Level Quality and Tube Suspension

The body is machined from durable aluminium, and the tubes are mounted on a special suspension system developed over months of testing to reduce microphonics to a minimum. ONIX is candid that no tube design eliminates microphonics entirely: in some conditions, such as tapping or dropping the unit, they can still be audible when tube mode is active. The XI2 is also power efficient, so it draws less from the connected device’s battery.

Cables, Connectors and the Eddict Player App

An ONIX OL1 cable made from silver-plated copper is included, and the universal USB-C connector makes it easy to swap in a longer or higher-grade cable. Standard 3.5mm and 4.4mm outputs cover both headphone types. The Eddict Player companion app adds control over volume, gain, output mode, digital filters, balance, display brightness and screen timeout, so the XI2 can be configured in detail rather than just plugged in and used.

Specifications

• Model: ONIX Beta XI2
• Product Type: USB dongle DAC and headphone amplifier with dedicated tube output
• DAC: 2 × Cirrus Logic CS43198
• Operational Amplifier: Dual OPA1662
• Buffers: Quad BUF434A
• Tube Output: Dual JAN6418 tubes with dedicated suspension system
• Output Modes: Transistor mode and Tube mode
• USB Modes: UAC 1.0 / UAC 2.0
• USB Connector: Universal USB-C (cable easily changed)
• Hi-Res Support: 768kHz / 32-bit and DSD512
• Display: 0.87-inch screen
• Controls: Hardware buttons for volume and playback; on-unit settings
• Sampling Rate Indicator: Multicolour LED — blue up to 48kHz, green up to 96kHz, yellow up to 192kHz, purple for highest PCM, white for DSD
• Companion App: Eddict Player (volume, gain, mode, filters, balance, brightness, screen timeout)
• 3.5mm Output — Transistor Mode (Low Gain): 45mW @ 32Ω
• 3.5mm Output — Transistor Mode (High Gain): 180mW @ 32Ω
• 3.5mm Transistor Mode THD+N: 0.0006% (A-weighted @ 2V)
• 3.5mm Transistor Mode Dynamic Range: 124dB
• 3.5mm Transistor Mode Channel Separation: 73dB
• 3.5mm Transistor Mode Signal-to-Noise Ratio: 124dB
• 3.5mm Transistor Mode Noise: 116dB
• 3.5mm Transistor Mode Output Impedance: 0.3Ω
• 3.5mm Output — Tube Mode (Low Gain): 37mW @ 32Ω
• 3.5mm Output — Tube Mode (High Gain): 152mW @ 32Ω
• 3.5mm Tube Mode THD+N: 0.06% (A-weighted @ 2V)
• 3.5mm Tube Mode Dynamic Range: 122dB
• 3.5mm Tube Mode Channel Separation: 73dB
• 3.5mm Tube Mode Signal-to-Noise Ratio: 122dB
• 3.5mm Tube Mode Noise: 114dB
• 3.5mm Tube Mode Output Impedance: 0.3Ω
• 4.4mm Balanced Output — Transistor Mode (Low Gain): 180mW @ 32Ω
• 4.4mm Balanced Output — Transistor Mode (High Gain): 550mW @ 32Ω
• 4.4mm Transistor Mode THD+N: 0.0008% (A-weighted @ 4V)
• 4.4mm Transistor Mode Dynamic Range: 128dB
• 4.4mm Transistor Mode Channel Separation: 107dB
• 4.4mm Transistor Mode Signal-to-Noise Ratio: 128dB
• 4.4mm Transistor Mode Noise: 114dB
• 4.4mm Transistor Mode Output Impedance: 0.6Ω
• 4.4mm Balanced Output — Tube Mode (Low Gain): 152mW @ 32Ω
• 4.4mm Balanced Output — Tube Mode (High Gain): 550mW @ 32Ω
• 4.4mm Tube Mode THD+N: 0.06% (A-weighted @ 4V)
• 4.4mm Tube Mode Dynamic Range: 127dB
• 4.4mm Tube Mode Channel Separation: 107dB
• 4.4mm Tube Mode Signal-to-Noise Ratio: 127dB
• 4.4mm Tube Mode Noise: 114dB
• 4.4mm Tube Mode Output Impedance: 0.6Ω
• Frequency Response (all outputs): 20Hz–40kHz (−0.5dB)
• Body: Durable aluminium construction
• Dimensions: 69.8 × 39 × 14mm
• Weight: 45.3g

What’s Included

• ONIX Beta XI2 USB dongle DAC
• ONIX OL1 cable (silver-plated copper)
• Protective case
• Quick start guide
• Warranty card