Anubis FAQ.

Which kind of PoE (Power over Ethernet) is compatible with Anubis ?

The Anubis PoE module is compatible with the 802.3at PoE standard.
802.3af is not compatible with Anubis.
https://en.wikipedia.org/wiki/Power_over_Ethernet

Does Anubis include redundant Power Supply?

Anubis can alternatively be powered from PoE (Power over Ethernet) or in parallel to the DC Power (9-15V), if redundancy is required.

PoE requirements:

• A suitable PoE+ equipped switch and/or external midspan PoE+ injector

• IEEE 802.3at class 0 Power-over-Ethernet standard

• 0 V (Min) – 48.0 V (Typical) - 57.0 V (Max) @ 1–2 A

If you use both power sources simultaneously and lose one of the source, redundancy is assured without any interference.

With Anubis SPS, when using both the DC power supply and PoE (with a PoE injector) which power source is primary and secondary? 

It will depend on the voltage level presented at the DC power input compared to the internal regulator of the Anubis PoE which outputs 12V.
If the DC jack is plugged as well, the primary supply will be the one with the highest voltage (comparing to the Anubis internal voltage level of 12VDC of the PoE regulator). We recommend the use of a protected/filtered voltage source with a voltage above 12VDC (up to a maximum of 15VDC on the barrel jack). In this case, you are ensured that the primary supply is the regulated and filtered supply.

What exactly is the AD Dual Gain 32bit circuitry?

While based on the extensive experience of Merging’s Horus and Hapi Preamp and AD converter design, the Anubis engineered Dual Gain 32bit A/D circuitry takes Analog/Digital Conversion design one step further. While using 2 A/D converter channels per input as, in the Horus & Hapi design, those two A/D converters are not driven in parallel by a single Preamp stage but the Anubis provides for two gain-ranged separate Analog front-ends, each driving its own A/D converter channel. The signals out of each AD converter is then combined seamlessly in an optimal way to both expand the headroom and lower the noise floor, providing huge dynamic range with ample headroom. One main advantage of this topology is the considerable additional freedom and safety implied by not having to spend much time and effort to adjust the input Gain to maximize the program level range between input circuitry noise and clipping level of the A/D converter. An important side benefit of that topology is also the total absence of any clicks when adjusting the Preamp Gain steps, as those can be entirely processed in the digital domain. More details are available in the Anubis User Manual.

What is the AD Split Channel feature?

The Dual Gain 32bit circuitry not only includes two inputs separate Gain but as well on each channel two separate Gain for independent dual outputs. This being the AD Split Channel feature. Each one of the Anubis 4 inputs channels can be split and have its independent Gain and Cut feature. Meaning that the Gain of a single Microphone can be split into two Gains for the same unique input channel.

Split Channel examples:

• Typically, an AD could be used for the recording device and have its split channel used for the FOH.

• Independently control the FOH & Monitoring Microphone Gains without any conflict

• The Split channel gives the operator the possibility to cut an input signal to the FOH while monitoring the same channel split that would be routed to another Monitoring set (e.g. Headphones). For signal check, changing a defective cable or searching for a proper sound or instrument FX, all this while muting the FOH feed.
  
  

Please elaborate whether you use pure 1bit or multi bit conversion and the measure taken to ensure proper signal fidelity in decimation to DXD or more conventional configurations like 88.2kHz 24bit or 176.4/24?

For now the entire DSD signal path, except for what regards the two conversion start and endpoints (AD and DA conversion) is pure 1-bit. However we do hope that we'll be able to offer added functionality via a future firmware update, that will allow users to also mix in DSD with similar convenience as they now experience in PCM. For that obviously multi-bit conversion will be mandatory but it is expected that no decimation will be required at any step. Hence the DSD signal processing chain will be entirely operating at its native sampling rate of 2.8 MHz (DSD64), 5.6 MHz (DSD128) or 11.2 MHz (DSD256).

Do you expect similar sound fidelity in irregular decimations to 96kHz or 192kHz?

Yes, with the current abundance of DSP processing power and large wordlength capabilities offered by modern CPU/DSP/FPGA processing, there is essentially no measurable difference between integer and complex ratio SRC when properly implemented.

Do the Anubis DA have DC coupled outputs?

Both Anubis Pro and Premium have DC coupled outputs circuitry, as do Merging’s Horus and Hapi.

How to connect a balanced line output to an unbalanced input

Contrary to Horus and Hapi DA8/P Line outputs, the MERGING+ANUBIS outputs are electronically floating (similar to transformer-based) and will therefore operate nominally with either Hi or Lo shorted to ground, as would be the case when connecting to an unbalanced input.

To connect the MERGING+ANUBIS to an unbalanced input using the balanced outputs, it is recommended to do so as shown in Figure below.

Open

Is the latency roundtrip (ADC to DAC) of an Anubis lower than an Hapi or Horus

Not only is it a few samples lower but the Anubis as well includes an internal FPGA-based DSP Mixer with ultra-low latency for the performer foldback, making sure that your musicians monitor themselves without any perturbing latency (e.g. in Live concerts or during Recording sessions). Refer to the Anubis User Manual, specification chapter for more details.

Can I use the Anubis ultra-low latency Mixer for my Horus or Hapi IO’s?

Yes, the Anubis is a great asset for owners of Horus and Hapi as you can already route and mix IO Streams coming from Horus or Hapi (or any RAVENNA AES67 compliant device) and create ultra-low latency Mixes for monitoring purposes or for musicians foldback. At the moment the connections have to be made using ANEMAN. Sources and Cues can be used in the Monitoring Mission to create Ultra Low Latency Monitoring Cues. A musician friendly Low Latency Mixer is also at the heart of the Music Mission.
Refer to the Anubis User Manual setup examples for more details.

What would the expected minimal Anubis AD to DA latency? And what about the ASIO driver?

Anubis has a roundtrip latency AD-DA that can be as low as 16 samples to which you must add 3 samples (FPGA side). So we are talking here of around 19 samples, depending of the configured settings.
Refer to the Anubis User Manual specification.
Our Merging Audio Device / RAVENNA/AES67 ASIO driver and latest firmware’s support a latency frame mode as low as 6 samples.

With Horus/Hapi we cannot duplicate the same output to different module, is Anubis the same?

With Anubis you can monitor the same outputs stream through different monitoring sets (Headphones, Speakers…). Because of the Anubis internal Mixer and its routing flexibilities you can easily Monitor the Output through your 1-2 Speakers and at the same time monitor it from the headphones output of your choice including the ones from remote devices that are AES67 compliant over your network.

What is the minimum supported impedance headphones?

The minimum impedance Merging tested for headphones is 16Ω. But nothing prohibits the user to connect even lower impedance headphones such as MrSpeakers Aeon (exhibiting as low as 13 to 14 Ohms Impedance).
If you are a user already running Anubis with low impedance headphones, you are welcome to provide your feedback to anubis@merging.com