[ruffrecords]

So one doesn't need drivers for various DAW's? 

I would have thought not. The operating system requires or provides drivers for the hardware so it can provide a defined interface to applications (DAW software). The DAW has no knowledge or direct connection with the hardware. Some USB devices are so common, like mice, keyboards and ordinary audio input/output,  that nearly all hardware complies with the requirements of a single Class driver. I think this now extends as far as 24 bit 192KHz devices.

There will always be some odd bits of hardware that require their own specific drivers but the trend is definitely towards driver standardisation.

Cheers

Ian

[gyraf]

Aah, that is a great development if so - I was under the impression that the generic usb audio drivers would not support anything north of 48/16

/Jakob E.

[mhelin]

I do wonder what they used for the 404. The dice2 chip?

They used and still use (in 404HD which is identical with original 404 having new firmware which can also be used to upgrade 404 to support 192 kHz sample rate) XMOS controller with Cirrus codecs.

Actually you could use almost any ARM Cortex M4 and above microprocessors to implement the USB stack, there are many USB DACs on market using Atmel parts (Amanero DAC, https://amanero.com/), but you can find some implementations for STM as well (search github for an example). I think someone was/is working on Teensy 4.x to add USB audio interface support as well.

Windows 10 already has driver support for USB Audio Class 2.0, don't know if they support multichannel I/O though, might be you will need the Thesycon drivers. Linux and Mac OS are fully class 2.0 compliant.

[ruffrecords]

I am a little concerned about a USB powered device creating an earth loop. Would it be possible to use, for example a Cirrus codec powered from the mixer supply optically coupled to a USB powered XMOS interface thereby maintaining galvanic isolation?


Cheers

Ian

[cyrano]

Optical spdif, eg TosLink?

You'd need one in, one out, of course. But perfect isolation. One of the reasons i'm an ADAT nut

[cyrano]

Next Time you work alongside the original pcm290x design team, give me a call...

I do own a bunch of USB 1.1 compliant devices. And all of those work perfectly with Linux or MacOS. Some are 6/2, some 2/6 @ 48 kHz. These can only do 96 kHz with a 2/2 config. The Behringer FW interfaces also support FW audio class operation.

I also have a number of USB 2 audio class compliant devices. And some of those support 96 kHz. Not 192, as they are somewhat older.

I use all of them @48 kHz, but I've tested it. Most of these devices were orphaned, because their owner couldn't get them to work on Windows...

The only reason I keep them, is because once in a while I can give them to someone and they don't end up on the big pile.

I've bought the stick type USB thingies by the dozen, for projects. But I can't give you a link, cause that was a while ago and <5$ products tend to change a lot.

They all work on Linux and MacOS. Even some of these support higher bitrates, these days. Some even have a DSP, that's not always used. But they are typical one-chip solutions of lesser known (for me at least) Chinese brands. Some of these sound pretty OK, for their price. Some have DC on the output, cause, you know, a cap there costs 5 cents.

[winner]

I suggest to use "c-media108" although it is a 48000 chip, but it has a USB interface, the most important thing is that it is very cheap, MAC/WINDOWS is free of drivers, and has I2S signal output, to external DAC and external ADC I2S signal Input, SPDIF signal output, external DAC is CS4398, CS4398 is also a cheap and easy-to-use thing; the total signal link USB->CM108AH->I2S->CS4398->DAC

[ruffrecords]

Optical spdif, eg TosLink?

You'd need one in, one out, of course. But perfect isolation. One of the reasons i'm an ADAT nut

Not necessarily - I was thinking I2S sources drive the LED in an opto-coupler the outputs of which feed the corresponding I2S input on the other device. A bit like the way feedback is galvanically isolated on an SMPS.

Cheers

Ian

[volker]

There are special ICs for that purpose: https://www.analog.com/en/analog-dialogue/articles/digital-isolators-in-medical-and-industrial-apps.html

[ruffrecords]

There are special ICs for that purpose: https://www.analog.com/en/analog-dialogue/articles/digital-isolators-in-medical-and-industrial-apps.html

Excellent, so you can easily galvanically isolate the USB bus.

Cheers

Ian

[mhelin]

Not necessarily - I was thinking I2S sources drive the LED in an opto-coupler the outputs of which feed the corresponding I2S input on the other device. A bit like the way feedback is galvanically isolated on an SMPS.

Cheers

Ian

SI8662BC will do the job...

[abbey road d enfer]

Excellent, so you can easily galvanically isolate the USB bus.

Cheers

Ian

https://www.amazon.fr/GeeekPi-ADUM3160-Isolateur-Isolement-Protection/dp/B07QPN951P/ref=sr_1_6?adgrpid=71422994049&dchild=1&gclid=Cj0KCQjwpZT5BRCdARIsAGEX0zlcMutqY4kRnrQ8L876jE6LPy4-Ljg_5X7ByyGmEuifc32FIhql8TgaAoGHEALw_wcB&hvadid=341734158678&hvdev=c&hvlocphy=9056208&hvnetw=g&hvqmt=b&hvrand=10541068217829121468&hvtargid=kwd-300796253219&hydadcr=7528_1752999&keywords=usb+power+isolator&qid=1596343811&sr=8-6&tag=googhydr0a8-21

[ruffrecords]

https://www.amazon.fr/GeeekPi-ADUM3160-Isolateur-Isolement-Protection/dp/B07QPN951P/ref=sr_1_6?adgrpid=71422994049&dchild=1&gclid=Cj0KCQjwpZT5BRCdARIsAGEX0zlcMutqY4kRnrQ8L876jE6LPy4-Ljg_5X7ByyGmEuifc32FIhql8TgaAoGHEALw_wcB&hvadid=341734158678&hvdev=c&hvlocphy=9056208&hvnetw=g&hvqmt=b&hvrand=10541068217829121468&hvtargid=kwd-300796253219&hydadcr=7528_1752999&keywords=usb+power+isolator&qid=1596343811&sr=8-6&tag=googhydr0a8-21

Thanks Abbey. I had no idea such things existed.

Cheers

Ian

[chilidawg]

Another alternative is B0505S DC-DC isolator (5V 1A)
I got mine for $3 each from a local vendor.

Single released and album follows now + Youtube links to single and live version

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