Fachmagazin für veranstaltungstechnik

REVIEW FROM ISSUE 1 I 2020

Dante-Interface

Neutrik NA2-IO-DPRO

www.production-partner.deTest Dante-Interface Neutrik NA2-IO-DPRO

Dante-Interface

NeutrikNA2-IO-DPRO
Neutrik‘s new Dante interface is equipped with line level inputs and complete
microphone inputs as well as digital AES/EBU inputs and outputs. How do thenetwork features and audio performance look like?
Copy and measurements: Anselm Goertz | Images: Dieter Stork

Neutrik NA2-IO-DPRO with two analogue inputs andoutputs each, which can optionally also be used for digital
AES/EBU audio signals on CH2
2Production partner 1/2020

Production Partner’s issue 4/19
already tested the NA2-IODLINE, the first Neutrik-Danteinterface from the NA2-IO

series.
Just in time for the new year, we received a further model with the NA2-IODPRO: while the DLINE is equipped withline level inputs and outputs only, thenew DPRO model also features two complete microphone inputs, two line level
outputs as well as two inputs and outputs each for digital AES/EBU audiosignals.
Externally, the DPRO maintains itsDPRO Controller for setting the NA2-IO-DPRO. For the inputs and outputs,
fine resolution level indicators are included that light up yellow from -18 dBfs
compact metal housing with a solid ruband red from -3 dBfs onwards
ber coating, which makes the small device slip-resistant and protects it at thesame time. On the front panel, the NA2-IO-DPRO features
comes to the Dante module, Neutrik opted for a Broadway
two XLR inputs and outputs, while the primary and secondchip which – in contrast to the Ultimo X2 featured in theary network connectors can be found on the rear. When it
DLINE – also allows a redundant network connection orTest Dante-Interface Neutrik NA2-IO-DPRO

daisy chaining with 1 Gbps. The supported sample rates are 44.1 k, 48 k,
88.2 k and 96 k. Power is supplied exclusively via PoE with a maximum
power consumption of 6 W. If theswitch used does not offer PoE, a simple PoE injector according to IEEE
802.3at or af standard can also beused.
The front panel is interesting, as users might miss digital AES/EBU inputs and outputs at first. A closer
look, however, reveals that each of
the analogue inputs or outputs’ CH2
has a double function and is labelled
QSYS integration of the Neutrik DPRO
with “ANA/AES”. Users do not have toswitch or carry out any settings for the respective signal(SRC), which accepts all signals up to a sample rate of 216
type: a digital AES/EBU source or sink is always assumed tokHz and adjusts them to the Dante network’s respective
be as such and the device is set accordingly if only CH2 issample rate. Additional LEDs on the inputs indicate Signalconnected. The signal is not checked in the process; the dePresent, 48 V Phantom Power as well as an active high-pass
vice only detects if there is a connection only in CH2.
filter and/or active PAD. There is only one LED at each output for the mute function.
Whether the inputs or outputs expect an analogue or a
All this is set via a corresponding small software, thedigital signal is optically indicated by a green or red LED.
The digital input is equipped with a Sample Rate Converter
DPRO controller. The software automatically recognises theassociated devices in the network andalso allows direct access to the Dantecontroller. All parameters including Mic/Line, Preamp Gain, PAD, HPF, and phantom power can be set via the interface.
When it comes to the outputs, a mutefunction and faders for the output levelare included.
The DPRO is also ready for QSYS aswell as for Yamaha’s CL and QL mixing
consoles. Yamaha will integrate theNeutrik DPRO in the CL and QL consoles’
firmware update to v.5.6 in spring 2020.
The plug-in for integration into theQSYS Designer software has also been
completed and, as of January 2020, iscurrently being approved by QSC.
Neutrik expects a release within thenext weeks. There is no need tochange the DPRO’s firmware itself,
Yamaha CL/QL consoles will also be able to integrate the Neutrik DPRO
everything is already prepared in thisdirectly from the console surface in the futurerespect.
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Test Dante-Interface Neutrik NA2-IO-DPRO

Two network connections on the NA2-IO-DPRO’s rear

AD section and preamps
All measurements for the Neutrik NA2-IO-DPRO were performed with a sampling rate of 96 kHz. Starting with theanalogue inputs, the frequency response, the signal-tonoise ratio and the distortion values or distortion spectra
were measured. The latter also includes a measurement of

the transient or dynamic intermodulation distortion (alsocalled DIM or TIM), as this measurement is said to correlate
well with a test device’s sound characteristics.
Fig. 1 first shows the two input channels‘ frequency
responses, standardised to 0 dB at 1 kHz. For this, themeasurement graphic covers a frequency range fromFrequency response of analogue inputs CH1Interference spectra of the analogue inputs with sum(blue) and CH2 (red) at minimum gain (solidvalues of -114 dBfs at minimum gain (red, blue) and ofcurves), at maximum gain (dashed) and with 80 Hz-81 dBfs at maximum gain (green, magenta); both values

high-pass filter. All curves are standardised

are linearly weighted (Fig. 2)

to 0 dB at 1 kHz (Fig. 1)
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Test Dante-Interface Neutrik NA2-IO-DPRO

THD+N as a function of the input level for CH1 (blue) and CH2

Distortion spectrum at 1 kHz measured via the analogue(red). The clip limit or sensitivity for 0 dBfs is +24.7 dBu input

inputs at minimum gain and with an input level of +21 dBu

level at minimum gain and -42.1 dBu at maximum gain. Measure-corresponding to -3 dBfs on the digital side; CH1 (blue) andment at 1 kHz (solid line), 100 Hz (dashed) and 6.3 kHz (dotted)

CH2 (red, Fig. 4)(Fig. 3)5 Hz to 45 kHz. The measurement was carried out forsettings with a minimum gain of 0 dB in the preampand with a maximum gain of 67 dB. A third series of measurements shows the curve with an active 80 Hz 1st-orderhigh-pass filter (6 dB/Oct). Almost independent of thegain setting, the curves are, as expected, perfectly straight.
For a gain setting of 0 dB in mic mode, the analogue
input level for 0 dBfs on the digital side is +24.7 dBu. At amaximum gain of +67 dB, the input level for 0 dBfs is-42.1 dBu. In line mode, the 0 dBfs with active PAD are

Transient intermodulation distortion (TIM) of the analogue

Frequency response of analogue outputs CH1 (blue) andinputs as a function of the input level at minimum (red, blue)

CH2 (red). The curves are standardised to 0 dB at 1 kHz. Theand maximum (green, magenta) gain (Fig. 5)

maximum output level is +24 dBu for 0 dBfs on the digitalside (Fig. 6)

6

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Test Dante-Interface Neutrik NA2-IO-DPROon the sound than the odd harmonics(k3, k5, ...). Important for the tonal
characteristics is also the fast decreaseof harmonics towards higher orders.
Both are not quite achieved here. Onthe other hand, all harmonic distortion
components are 100 dB or more below
the fundamental wave, where it isopen to serious discussion whether
this can have any effect on the soundat all. Probably not.
The last measurement with agraphical display for the input section
concerns the transient intermodulation distortion (TIM), in which a 15
kHz sine wave is superimposed witha steep-edged 3.15 kHz rectangle. The
resulting intermodulations are evaluated. Fig. 5 shows the values again asa function of the analogue input level,
Interference spectrum at the analogue outputs with a total level of -88 dBu or -91 dBuwith A-weighting. The maximum output level is +24 dBu, which results in an S/N of 112 dB
which were also measured here foror 115 dB, respectively (Fig. 7))
gain settings of 0 dB and +67 dB. In
both settings, the NA2-IO-DPRO delivers good to very good results, especially again considering
also reached at +24.7 dBu – at +8.7 dBu without PAD. The
the high gain.
noise level measurements provide a signal-to-noise ratioof 114 dB evaluated linearly, of 116 dB A evaluated at 0 dB
gain and of 81 dB or 84 dBA at a maximum gain of 67 dB.
Together with the sensitivity of -42 dBu, this results in an
EIN (Equivalent Input Noise) of -123 dBu. With A-weighting,it is -126 dBu.
For the distortion measurements, the harmonic distortions were first measured as THD+N (total harmonic distortions and noise). Fig. 3 shows the curves as a function of
the input level measured for frequencies of 100 Hz, 1 kHz
and 6.3 kHz in microphone mode for the two gain settingsof 0 and 67 dB. The clip limits are then +24.7 dBu and-42.1 dBu respectively. At 0 dB gain, very good distortion
values of about -100 dB are achieved. Only at 6.3 kHz
does the curve begin to rise slightly at about 20 dB below
the clip limit. At maximum gain, the curves are congruent
regardless of the frequency and fall to a minimum of-83 dB. Considering the high amplification, this is alsoa very good value.
THD+N of the DA converters with amplifiers as a function of theoutput level. 0 dBfs on the digital side correspond to an analogue
In addition to the harmonic distortions value as a whole,output level of +24 dBu. Measurement at 1 kHz (solid line), 100 Hz
their spectral composition is also interesting. The even(dashed) and 6.3 kHz (dotted) (Fig. 8)
harmonics (k2, k4, ...) are said to have a more positive effect7

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Test Dante-Interface Neutrik NA2-IO-DPRO

Measurements
Neutrik NA2-IO-DPRORRP in € incl. tax

840 €Sample rate

44,1 / 48 / 88,2 /96 kHz

Dante module

Broadway

Number of analogue/
digital inputs:

2/2Input sensitivity+24.7... -42.1 dBu

S/N* @ min. gain

114 dB

S/N* @ max. gain

81 dB

IN* @ max. gain:

123 dBuCMRR @ 1 kHz72 dB

CTC @ 1 kHz

92 dB

Number of analogue/
digital outputs

2/2

Max. output+24 dBu

S/N* rel. to max. output

112 dB

CTC @ 1 kHz>100 dB

Internal resistance150 Ω(symmetrical)* A ll noise level values 20 Hz to 20 kHz
unweighted** In case of different values for the channels,
the lower value is shown in the summary

8Distortion spectrum at 1 kHz for a level of +21 dBu(-3 dBfs) at the analogue outputs; displayed in absolutevalues in dBu (Fig. 9)

are perfectly straight. When it comes to distortion, theDACs and the subsequent amplifiers in principle offer comparable measurements as were made for the ADCs. Fig. 8and 9 show the THD+N curves as a function of level at 100
Hz, 1 kHz, and 6.3 kHz as well as the FFT spectrum at 1 kHz.
The FFT spectrum was measured 3 dB below full scale andthus at an output level of +21 dBu. The diagram shows theresults in dBu. For the largest harmonic (k3) with a level of-79 dBu, this therefore results in a distortion of -100 dB.
For both measurements, the Neutrik interface therefore
achieves very good values.

DA section and amplifier

Summary

When it comes to the output, the DACs with the subsequent analogue amplifiers are responsible for the signaltrans-mission. The NA2-IO-DPRO interface’s maximum output voltage is +24 dBu. In contrast, the noise level measured at the analogue outputs is linearly weighted at -88
dBu and at -91 dBu with A-weighting, resulting in a S/N of112 dB or 115 dB with A-weighting when it comes to thenoise component. Fig. 7’s interference spectrum consists
exclusively of white noise and is completely free of monofrequency components. Also flawless is the frequency response of the NA2-IO-DPRO’s outputs. The curves in Fig. 6

With the NA2-IO-DPRO, Neutrik launches another Dante interface that offers everything one could wish for – withline level inputs and complete microphone inputs as well
as digital AES/EBU inputs and outputs. Thanks to the Audinate Broadway chip, primary and secondary network interfaces are now also available and data can be transmittedwith up to 1 Gbps. All this is contained in a very solidly
constructed, tiny enclosure and delivers a consistently
good to very good performance. For a list price of 840 €,the NA2-IO-DPRO is a Dante interface that can be used in
all kinds of situations. ■
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