Behringer's UltraNet reversed

[cyrano]

Christian Noeder, a German engineer has reverse engineered Behringer's UltraNet as used in the X32 family and the S16 monitoring system. It transports 16 channels at 24 bit, 48 kHz.

The site is in German, but the video explaining the protocol is in English.

https://www.pcdimmer.de/index.php/hardware/fpga/ultranet-receiver

The software is available from Christian's github. There's a Wiki and even a forum on the site.

 

[Michael Tibes]

Thank you, very interesting! The text can actually be switched to english using the flags in the top right corner

 

[capacitorless]

Good translation to English! I just learned that DSD is really a Sony marketing term for 1 bit 2 level PDM, there's an Arduino with FPGA for 80 usd, programmable using free FPGA software from Intel. Thanks @cyrano !

 

[cyrano]

Thank you, very interesting! The text can actually be switched to english using the flags in the top right corner

Sometimes, I'm a blind man...

 

[mhelin]

That guy (German engineer) is like almost ten years late:
https://github.com/tuck1s/UltranetReceiver

 

[cyrano]

That guy (German engineer) is like almost ten years late:
https://github.com/tuck1s/UltranetReceiver

Only 8 channels. Christian's solution has all 16...

This is the accompanying website:

https://thetucks.com/post/differential-line-receiver-for-behringer-ultranet/

Not much info at all.

 

[mhelin]

That Steve Tuck's hacking was discussed on diyaudio forums ten years ago, I think he built also a 16-channel version. In addition you don't need that fancy FPGA stuff or even Xcore to implement the thing, just a SPDIF receiver chip (or pair) and a Teensy or similar to mix the channels (in addition to the MagJacks) . An SPDIF receiver like CS8416 already has all you need including the differential line receiver for which Steve used an additional chip (above link). CS8416 (or some AKM ones) can embed the framing data into the audio stream which the software can then use for framing. So the Ultranet "protocol" is nothing more than AES3 (https://en.wikipedia.org/wiki/AES3), Behringer just used the Z preamble to frame the eight channels and mark the start of the audio block. The physical connector (ethernet) was a bad choice, many people "accidentally" connected cables to the usual inhouse internet cabling burning the resistors inside the boxes (I've too got a second hand P16-I with a few burned 56 ohm resistors in it's outputs).