• Registered: 2016-06-18
  • Posts: 29

Topic: Product/technology idea: Better digital audio (incl. clock) over USB

I wondered if RME might be interested in working with synth and other digital audio equipment manufacturers to develop a new USB digital audio standard which allowed RME audio interfaces to provide device USB ports for digital audio I/O connections to synths, audio sources, etc.
The standard could include a clock source but, e.g. for devices not capable of external clocking, could include sample rate negotiation/requests and of course in such cases an RME audio interface could apply SRC to incoming audio.
It could also include high-precision MIDI and perhaps new standards for HW audio/sound/note controllers.
It would also ultimately allow driverless/low-latency connection from audio device to PC/Mac as well when OS support provided and perhaps one day be used by audio interfaces themselves for both host and devices connection (chaining arrangements with interface providing clock source?)

Just an idea. And perhaps it should be USB-C to be future-proof.

2 Reply by ramses (edited by ramses 2018-07-28 14:14:03)

  • ramses
  • DAW Mastermind
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  • Registered: 2012-10-14
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Re: Product/technology idea: Better digital audio (incl. clock) over USB

You might come into several issues.
USB is more complex and has much/more protocol overhead and thus needs more CPU power.
So more CPU power would be required on the keyboard itself and also on this "next generation" recording interface.
By this you add two times latency for the processing of this data and maybe also by the USB protocol itself.

Recording Interfaces have usually limited FPGA resources, so this all would need to be handeled additionally per connected USB keyboard device. FPGAs are expensive. The usual companies producing the usual keyboards would not take FPGAs and implement USB therein. They would buy simply USB controllers from the market from which we know that they have often compatibility problems.

More technical aspects in terms of data transport: How do you keep data in sync, if you need to transfer audio and control data (like MIDI).

And all these efforts sum up with each additional USB port that you would require for such an interface.
How do you design this ?
One USB port with a HUB for many devices ? Or dedicated USB controller per device ? (-> costs, complexity)
This is from resource / price perspective much of an overhead.

Then you would additionally get all the incompatibility problems by USB controllers not 100% applying to the standard that we have now luckily only between PC and recording interfaces additionally between the recording interface and all the devices that you want to connect to the recording interface via USB ?

On top you get with USB additional problems, as cable lengths are limited. For a standard USB2 cable 5m.
With a digital cable you can achive longer distances, optical SPDIF up to 15 or even 20m.

This all makes for me absolutely no sense from whatever angle you look at it. Cost, performance, latency, stability, compatibility, ...

You should maybe better ask for
- keybords with digital output like SPDIF or AES. For this you can take standard solutions where the transport of digital data is much easier to process, with less latency and where standards are already there
- and if we then really have more digital devices for more digital ports on recording interfaces. But this makes only sense if the amount of devices to be connected digitally would really increase.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13