The HDSPe AoX PCIe x4 audio interface cards combine dual network ports with headphone output, AES3, MIDI, and internal expansion headers for up to four MADI ports. Whether used in a Thunderbolt™ expansion chassis or built into DAWs or audio processors, these cards send and receive up to 512 channels of audio and provide numerous mixing and routing capabilities.

Occupying only a single slot, the PCIe x4 interface transmits and receives up to 512 channels of network audio signals on two separate RJ45 connectors. The network audio channels can partially be replaced (or extended in case of the Milan® version) with MADI signals by adding up to two optional dual optical or dual coaxial extension cards. It is therefore possible to integrate four MADI input signals, four MADI output signals plus up to 256 network audio channels per direction within a single audio interface for the first time – on macOS and Windows.

In comparison to these massive channel counts, the ¼” stereo headphone jack occupies a lot of space on the card – for good reasons, because it allows monitoring of any signal reaching the card – from the computer, the network, or the optional MADI inputs. And to add one more signal to the mix – a stereo AES3 digital I/O is available together with MIDI on a breakout cable, making it a versatile and full-fledged professional interface.

Flexible Mixing & Routing with TotalMix

The vast number of channels can be managed by the user in two steps. Using a driver dialog or web interface, the user first adjusts the network vs. optional MADI channel count, and then pre-selects which inputs reach the 256 channel TotalMix engine. The remaining 256 channels are passed straight through. All 512 channels are visible to the DAW for recording. TotalMix offers its basic functionality without effects, but with all the great benefits such as presets, layouts, loopback, sub-mixes, and many more.

Tech specs

Analog Inputs

RCA (Standard D-Sub Breakout cable)

Input: Cinch (RCA), unbalanced
Input impedance: 18 kOhm
Input sensitivity switchable +24 dBu, +19 dBu, +13 dBu, +4 dBu @ 0 dBFS
Signal to Noise ratio (SNR) @ +19/24 dBu: 117 dB RMS unweighted, 120 dBA
Signal to Noise ratio (SNR) @ +13 dBu: 116 dB RMSu nweighted, 118 dBA
Signal to Noise ratio (SNR) @ +4 dBu: 112 dB RMSu nweighted, 114 dBA
Frequency response @ 44,1 kHz, -0,1 dB: 7 Hz – 20.5 kHz
Frequency response @ 96 kHz, -0,5 dB: 3 Hz – 45,5 kHz
Frequency response @ 192 kHz, -1 dB: 2 Hz – 92 kHz
THD @ -1 dBFS: -114 dB, 0,0002 %
THD+N @ -1 dBFS: -110 dB, 0,0003 %
Channel separation: > 110 dB

XLR (optional D-Sub Breakout cable)
as RCA, except:

Input: XLR, servo-balanced
Input impedance balanced: 36 kOhm, unbalanced: 18 kOhm
Signal to Noise ratio(SNR) @ +4 dBu: 116 dB RMS unweighted, 118 dBA

Analog Outputs

RCA (Standard D-Sub Breakout cable)

Output: Cinch (RCA), unbalanced
Output impedance+19/+13 dBu: 75 Ohm. +4/-2 dBu: 80 Ohm
Output impedance switchable +19, +13 dBu, +4 dBu, -2 dBu @ 0 dBFS
Signal to Noise ratio (SNR) @ +19 dBu: 117 dB RMS unweighted, 119 dBA
Signal to Noise ratio (SNR) @ +13 dBu: 116 dB RMS unweighted, 118 dBA
Signal to Noise ratio (SNR) @ +4 dBu: 114 dB RMS unweighted, 116 dBA
Signal to Noise ratio (SNR) @ -2 dBu: 110 dB RMS unweighted, 112 dBA
Frequency response @ 44.1 kHz, -0,1 dB: 10 Hz – 20,2 kHz
Frequency response @ 96 kHz, -0,5 dB: 4 Hz – 44,6 kHz
Frequency response @ 192 kHz, -1 dB: 3 Hz – 83 kHz
THD @ 0 dBFS: < -107 dB, 0,0005 %
THD+N @ 0 dBFS: -105 dB, 0,0006 %
Channel separation: > 110 dB

XLR (optionales D-Sub Breakout cable)
as RCA, except:

Output: XLR
Output impedance +24/+19 dBu: 150 Ohm, +13/+4 dBu: 160 Ohm
Output level switchable +24 dBu, +19 dBu, +13 dBu, +4 dBu @ 0 dBFS
Signal to Noise ratio (SNR) @ +24 dBu: 117 dB RMS unweighted, 120 dBA

Phones
as RCA, except:

Output: 6.3 mm TRS jack, unbalanced, stereo
Output impedance: 0.1 Ohm
Signal to Noise ratio (SNR) @ +19 dBu (Hi-Power): 117 dB RMS unweighted, 119 dBA
Signal to Noise ratio (SNR) @ +7 dBu (Lo-Power): 113 dB RMS unweighted, 115 dBA
Output level at 0 dBFS, Hi-Power, load 150 Ohm or up: +19 dBu (6.9 V)
Output level at 0 dBFS, Lo-Power, load 16 Ohm or up: +7 dBu (1.73 V)
THD+N @ + 15 dBu, 32 Ohm load, 590 mW: -97 dB, 0.0016 %
Max power @ 0.1% THD 32 Ohm: 730 mW per channel

Digital Inputs

AES/EBU

1 x XLR, transformer-balanced, galvanically isolated, according to AES3-1992
High-sensitivity input stage (< 0,3 Vss)
SPDIF compatible (IEC 60958)
Accepts Consumer and Professional format, copy protection will be ignored
Lock Range: 28 kHz – 200 kHz

SPDIF

1 x RCA, transformer-balanced, according to IEC 60958
High-sensitivity input stage (< 0,3 Vss)
AES/EBU compatible (AES3-1992)
Accepts Consumer and Professional format, copy protection will be ignored
Lock Range: 28 kHz – 200 kHz

ADAT Optical

1 x TOSLINK, format according to Alesis specification
Standard: 8 channels 24 bit, up to 48 kHz
Double Speed (S/MUX): 4 channels 24 bit 96 kHz
Quad Speed (S/MUX4): 2 channels 24 bit 192 kHz
Bitclock PLL ensures perfect synchronisation even in varispeed operation
Lock range: 31.5 kHz – 50 kHz

Digital Outputs

AES/EBU

1 x XLR, transformer-balanced, galvanically isolated, according to AES3-1992
Output level 4,0 Vss
Format Professional according to AES3-1992 Amendment 4
Single Wire mode, sample rate 28 kHz up to 200 kHz

SPDIF

1 x RCA, transformer-balanced, according to IEC 60958
Output level Professional 2.3 Vpp, Consumer 1.0 Vpp
Format Professional according to AES3-1992 Amendment 4
Format Consumer SPDIF according to IEC 60958
Single Wire mode, sample rate 28 kHz up to 200 kHz

ADAT

1 x TOSLINK, format according to Alesis specification
Standard: 8 channels 24 bit, up to 48 kHz
Double Speed (S/MUX): 4 channels 24 bit 96 kHz
Quad Speed (S/MUX4): 2 channels 24 bit 192 kHz

Digital

Clocks: Intern, ADAT In, SPDIF In, Sync In, optional Word clock In / LTC in
Jitter suppression of external clocks: > 50 dB (2,4 kHz)
Effective clock jitter influence on AD and DA conversion: near zero
PLL ensures zero dropout, even at more than 100 ns jitter
Digital Bitclock PLL for trouble-free varispeed ADAT operation
Supported sample rates: 28 kHz up to 200 kHz

MIDI

1 x MIDI I/O via 5-pin DIN jacks
Galvanically isolated by optocoupled input
Hi-speed mode: Jitter and response time typically below 1 ms
Separate 128 byte FIFOs for input and output

RME HDSPe AoX-M