RME ADI-2/4 Pro EX AD/DA Converter And USB Headphone Amplifier

RME ADI-2/4 Pro EX AD/DA Converter

The RME ADI-2/4 Pro EX AD/DA Converter combines two-channel analog-to-digital conversion, four-channel digital-to-analog conversion, USB audio connectivity, and headphone amplification. It supports internal sample rates up to 768 kHz with 32-bit converters. Balanced analog connections, digital format conversion, and onboard audio processing serve recording, mastering, monitoring, and vinyl digitization workflows.

Engineers can use this USB converter for studio mastering, a headphone amplifier for critical listening, or an audio interface for vinyl recording. Independent line and balanced headphone operation allows different signals to reach speakers and headphones simultaneously. Rear TRS outputs can follow the line or headphone signal path, providing additional routing options for mastering inserts. Phono equalization and selectable input impedance accommodate turntable integration.

ESS ES9823Pro and ES9039Q2M converters work alongside RME's SteadyClock EX clock system, factory-calibrated to an accuracy of ±1 part per million. Digital signal processing (DSP) provides parametric equalization, crossfeed, tone adjustment, and volume-dependent loudness compensation. A color IPS display presents meters, a spectrum analyzer, and connection status. Class-compliant USB operation supports compatible computers and mobile devices, while RME's Windows driver supplies ASIO and WDM connectivity.

Key Features

• Two-Channel A/D And Four-Channel D/A: Combine analog capture, playback conversion, and monitoring in one compact desktop unit.
• 32-Bit Conversion Up To 768 kHz: ESS converter hardware supports high-resolution recording, playback, and measurement applications.
• Independent Headphone Monitoring: Balanced headphone operation leaves the rear line outputs available for a separate signal.
• Flexible Analog Routing: Balanced XLR and rear TRS connections support studio integration, with selectable signal paths for the TRS outputs.
• Onboard Sound Processing: Five-band parametric EQ, bass and treble controls, crossfeed, and loudness adjustment tailor monitoring without an external processor.
• Digital Format Connectivity: AES/EBU, coaxial S/PDIF, and optical S/PDIF with ADAT support accommodate multiple digital sources.
• Turntable Integration: RIAA phono equalization, selectable input impedance, and a dedicated ground terminal support vinyl playback and digitization.
• SteadyClock EX Synchronization: Factory-calibrated timing and adjustable internal sample rate support precise integration with external equipment.

Technical Specifications

• Brand: RME
• Model: ADI-2/4 Pro EX
• Conversion Channels: 2 analog-to-digital; 4 digital-to-analog
• Converter Architecture: 32-bit
• A/D Converter: ESS ES9823Pro
• D/A Converter: ESS ES9039Q2M
• Internal Sample Rates: 44.1-768 kHz
• External Clock Sample Rates: 32-200 kHz
• USB Connection: Lockable USB-C; USB 2.0 compatible
• USB Audio Modes: Stereo, 2 inputs/2 outputs; multichannel, 6 inputs/8 outputs
• USB Class Compliance: USB Audio Class 2.0
• Computer Compatibility: Compatible macOS, iOS, Linux, and Windows systems; RME MADIface-series driver provides Windows ASIO and WDM support
• Additional Audio Format: DSD recording and playback
• Analog Inputs: 2 servo-balanced XLR/TRS combo connectors
• Analog Input Impedance At 1 kHz: 94 kOhm balanced; 47 kOhm unbalanced; switchable impedance available through the RIAA balanced option
• Input Reference Levels At 0 dBFS: +24, +19, +13, +7, and +1 dBu
• Extended Input Sensitivity: Digital gain provides settings from -5 down to -35 dBu
• Input Trim Gain: 0 to +6 dB in 0.5 dB steps
• Input SNR At +24 dBu: 125 dB AES17; 127 dBA
• Input SNR At +13/+19 dBu: 124 dB AES17; 126 dBA
• Input SNR At +7 dBu: 123 dB AES17; 125 dBA
• Input SNR At +1 dBu: 121.5 dB AES17; 123.5 dBA
• Input SNR At -5 dBu With Digital Gain: 117.5 dB AES17; 119.5 dBA
• Input SNR At -35 dBu With Digital Gain: 87 dB AES17; 89 dBA
• Input Frequency Response At 44.1 kHz: 0.4 Hz-20.5 kHz, -0.1 dB
• Input Frequency Response At 96 kHz: 0.2 Hz-44.5 kHz, -0.5 dB
• Input Frequency Response At 192 kHz: 0.15 Hz-91.5 kHz, -1 dB
• Input Frequency Response At 384 kHz: 0.15 Hz-175 kHz, -1 dB
• Input Frequency Response At 768 kHz: 0.15 Hz-290 kHz, -1 dB
• Input Total Harmonic Distortion (THD) At -1 dBFS: Below -127 dB; 0.000045%
• Input THD Plus Noise At -1 dBFS: -119 dB; 0.000112%
• Input Channel Separation: Greater than 130 dB at 1 kHz
• RIAA Connections: Unbalanced TS or balanced TRS/XLR
• RIAA Equalization Accuracy: Less than ±0.05 dB deviation from 20 Hz-20 kHz
• RIAA Selectable Balanced Impedance: 94 or 47 kOhm at 1 kHz
• RIAA Unbalanced Impedance With 47 kOhm Balanced Setting: 33 kOhm at 1 kHz
• RIAA Input Capacitance: 150 pF
• RIAA Sensitivity: At 0 dB gain, current reference level minus 15 dB; at +14/+20/+26/+32/+38 dB gain, 20/10/5/2.5/1.25 mV respectively
• RIAA Additional Trim: 0 to +6 dB in 0.5 dB steps
• RIAA Maximum Input At 0 dB Gain: Current reference level
• RIAA Maximum Input At +14 dB Gain: 114 mV; -16.6 dBu
• RIAA Maximum Input At +20 dB Gain: 57 mV; -22.6 dBu
• RIAA Maximum Input At +26 dB Gain: 28.4 mV; -28.7 dBu
• RIAA Maximum Input At +32 dB Gain: 14.3 mV; -34.7 dBu
• RIAA Maximum Input At +38 dB Gain: 7.2 mV; -40.6 dBu
• RIAA Digital Headroom: 15 dB relative to sensitivity at all gain settings
• RIAA SNR At +14/+20 dB Gain, 20 Hz-20 kHz: 88 dB; 92 dBA
• RIAA SNR At +26 dB Gain, 20 Hz-20 kHz: 80.5 dB; 85 dBA
• RIAA SNR At +32 dB Gain, 20 Hz-20 kHz: 74 dB; 78.5 dBA
• RIAA SNR At +38 dB Gain, 20 Hz-20 kHz: 68 dB; 73 dBA
• RIAA THD Plus Noise At +14/+20 dB Gain: -88 dB; 0.004%, measured over 20 Hz-20 kHz
• RIAA THD Plus Noise At +26 dB Gain: -81.5 dB; 0.0084%, measured over 20 Hz-20 kHz
• RIAA THD Plus Noise At +32 dB Gain: -74 dB; 0.019%, measured over 20 Hz-20 kHz
• RIAA THD Plus Noise At +38 dB Gain: -69 dB; 0.035%, measured over 20 Hz-20 kHz
• Rear Analog Outputs: 2 XLR and 2 impedance-balanced 1/4-inch TRS connectors
• Rear TRS Routing: Selectable Line 1/2 or Phones 3/4 signal path
• Analog Output Coupling: DC-coupled
• XLR Output Impedance At +24/+19/+13 dBu: 200 Ohm at 1 kHz
• XLR Output Impedance At +7/+1 dBu: 100 Ohm at 1 kHz
• XLR Maximum Output: +26.5 dBu at 0 dBFS
• XLR Output Reference Levels: +24, +19, +13, +7, and +1 dBu at 0 dBFS
• XLR Output SNR At +7/+13/+19/+24 dBu: 124 dB AES17; 126 dBA
• XLR Output SNR At +1 dBu: 121 dB AES17; 123 dBA
• Output Frequency Response At 44.1 kHz: 0 Hz-20.5 kHz, -0.1 dB
• Output Frequency Response At 96 kHz: 0 Hz-45.2 kHz, -0.5 dB
• Output Frequency Response At 192 kHz: 0 Hz-91 kHz, -1 dB
• Output Frequency Response At 384 kHz: 0 Hz-183 kHz, -1 dB
• Output Frequency Response At 768 kHz: 0 Hz-350 kHz, -3 dB
• XLR Output THD At 0 dBFS: Below -130 dB; 0.0000316%
• XLR Output THD Plus Noise At 0 dBFS: -119 dB; 0.00011%
• XLR Output Channel Separation: Greater than 130 dB at 1 kHz
• Rear TRS Output Impedance: 200 Ohm balanced; 100 Ohm unbalanced, at 1 kHz
• Rear TRS Maximum Output: +21.5 dBu at 0 dBFS
• Rear TRS SNR At +19 dBu: 124 dB AES17; 126 dBA
• Rear TRS SNR At +7/+13 dBu: 122 dB AES17; 124 dBA
• Rear TRS SNR At +1 dBu: 118.5 dB AES17; 120.5 dBA
• Headphone Connections: 2 unbalanced stereo 1/4-inch TRS outputs; balanced Pentaconn connection
• Headphone Power Modes: High Power, Low Power, and in-ear monitor (IEM)
• Unbalanced Headphone Output Impedance: 0.1 Ohm
• Unbalanced Headphone Maximum Level: +21.5 dBu; 9.2V with a load of 100 Ohm or higher
• Unbalanced Headphone SNR: High Power, 124 dB/126 dBA; Low Power, 122 dB/124 dBA; IEM, 120 dB/122 dBA
• Unbalanced Minimum Headphone Loads: IEM, 4 Ohm; Low Power, 8 Ohm; High Power, 24 Ohm
• Unbalanced Headphone Power At 0.1% THD Plus Noise: 0.288W per channel into 300 Ohm; 2.4W into 32 Ohm; 1.93W into 16 Ohm
• Headphone THD At +20 dBu Into 32 Ohm: -124 dB; 0.000057%, at 1.9W
• Headphone THD Plus Noise At +20 dBu Into 32 Ohm: -118 dB; 0.00011%, at 1.9W
• Unbalanced Headphone Channel Separation: 80 dB into 32 Ohm over 20 Hz-20 kHz
• Balanced Headphone Output Impedance: 0.2 Ohm
• Balanced Headphone Maximum Level: +27.5 dBu; 18.4V at 0 dBFS
• Balanced Headphone Reference Levels: IEM, +7 dBu/1.73V; Low Power, +13 dBu/3.46V; High Power, +25 dBu/13.8V
• Balanced Headphone SNR: High Power, 124 dB/126 dBA; Low Power, 123 dB/125 dBA; IEM, 122 dB/124 dBA
• Balanced Minimum Headphone Loads: IEM, 8 Ohm; Low Power, 12 Ohm; High Power, 40 Ohm
• Balanced Headphone Power At 0.1% THD Plus Noise: 1.15W per channel into 300 Ohm; 3.85W into 32 Ohm; 1.93W into 16 Ohm
• Balanced Headphone Channel Separation: Greater than 130 dB at 1 kHz
• Headphone Protection: Mute relays, overcurrent detection, individual DC protection, plug detection, and DSP-controlled operation
• Digital Input Lock Range: 28-200 kHz
• Accepted Digital Formats: Consumer and Professional
• AES/EBU Input: XLR via breakout cable; transformer-balanced, galvanically isolated; AES3-1992; 1Vpp sensitivity
• Coaxial S/PDIF Input: RCA via breakout cable; transformer-balanced; IEC 60958; sensitivity below 0.3Vpp; AES3-1992 compatible
• Optical Input: IEC 60958 S/PDIF; ADAT compatible
• AES/EBU Output: XLR via breakout cable; transformer-balanced, galvanically isolated; 2.7Vpp; AES3-1992 Amendment 4 Professional format
• Coaxial S/PDIF Output: RCA via breakout cable; 0.75Vpp; IEC 60958 Consumer format
• Optical Output: IEC 60958 Consumer S/PDIF
• Published Digital Output Rate Range: 44-200 kHz; single-wire operation for AES/EBU and coaxial S/PDIF
• Clock Sources: Internal, AES input, S/PDIF input, ADAT input
• Clock System: SteadyClock EX
• Internal Clock Accuracy: ±1 ppm
• Internal Sample-Rate Adjustment: ±50 ppm in 0.1 ppm increments
• External Clock Jitter Suppression: Greater than 50 dB above 1 Hz
• Clock Recovery: Phase-locked loop supports input jitter exceeding 100ns; additional digital bitclock PLL supports ADAT varispeed operation
• Headphone Digital Monitoring: ADAT channels 3/4 selectable as a source
• DSP Functions: Five-band parametric EQ, bass/treble adjustment, crossfeed, loudness compensation, RIAA equalization
• Display: IPS color panel with peak meters, 30-band analyzer, and digital connection/clock status overview
• Remote Control: MRC with 4 programmable buttons and access to 61 assignable functions and commands
• Software: ADI-2 Remote control application; DIGICheck audio analysis tools
• Ground Connection: Dedicated terminal for turntable grounding or earth connection
• Rackmount Compatibility: Optional RM19-III adapter
• Included Power Supply: External switching supply; 100-240V AC input; 12V DC output, 3.3A, 40W; lockable connector
• Power Consumption: 14W idle; 30W maximum
• Idle Current At 12V: 1.16A
• Standby Consumption: 170mW at 12V DC; 280mW at 230V AC
• Undervoltage Detection: Below 9V
• Overvoltage Disconnection: Above 16.5V
• Power Protection: Active fuse-less protection against incorrect polarity and overvoltage
• Operating Temperature: 5-40°C
• Relative Humidity: Below 75%, non-condensing
• Dimensions (Width x Height x Depth): 8.5 x 1.7 x 6.3 inches; 1U height

What's In the Box

• 1 x ADI-2/4 Pro EX
• 1 x MRC remote control with battery
• 1 x manual
• 1 x external 12V DC, 40W switching power supply with lockable connector and IEC socket
• 1 x power cord
• 1 x BOC968 AES/S/PDIF digital breakout cable
• 1 x 70.8-inch USB-C cable with one lockable end
• 1 x quick start guide