ADAT to multiple SPDIF (at least 2x24/96, ideally 4x24/48)

[mike7877]

I've been looking at the usual suspects from the usual suspects for an adapter to turn the ADAT optical port on my interface into at least two 24/96 SPDIF or ideally four 24/48s, but I haven't had any luck! All I can find is multi-channel ADCs and DACs which connect back through ADAT, nothing that's digital...

My interface is RME Babyface Pro (non-fs).
I've read that RME's driver supports up to three RME devices simultaneously, one has to be master while the other is slave.. I don't know how this can be done if my Babyface only has one ADAT out - if that has to go into another device's input and not a DAC, connecting the two for sync is pretty pointless because there's still just one available optical out (if the second device was another Babyface or interface with only one ADAT as well)

Do I have to buy a DigiFace for this? One of the reasons I got the Babyface 5 years ago was for its ability to expand ADAT to 2x 24/96 and 4x 24/48. Well that day has come, and I'm disappoint! lol
Hopefully not?

 

[gberchin]

The closest thing to it that I could find is the MCHStreamer, which can apparently receive 8-channel ADAT and output it as four separate I²S signals (see page 22-23 of the User Manual). Converting that to S/PDIF requires circuitry. There are some products available, but I could not find any that support 4 signals.

 

[Rja4000]

I'm not sure to understand your need.

I have several effect devices that allow ADAT chaining.
You just select which pair is used on each device, and the output + other ADAT channels (untouched) are sent to the ADAT output. You then connect next device to it, and so on.
The Babyface can do the same. That should be straightforward using Totalmix.

Also, any RME with 2 ADAT outputs, like the UFX II and, probably, the 802 fs, may use the ADAT out as SPDIF, so you can, for sure, send 4 ADAT input channels to 2 SPDIF optical outputs (+2 AES outputs that may comnect to coax SPDIF if needed)

Other than that, I know a few ADAT converters, like the RME ADI-192 DD or the Mutec MC-4 can split ADAT to several SPDIF or AES, but on coax or XLR, not optical.

Finally, maybe worth a try, the old Motu 2408 mk 3 have 3 ADAT I/O and 2 SPDIF Coax out.
It may be possible to split ADAT ins and send to the SPDIF, possibly even up to 192kHz.
The good thing is that those cards may be purchased very cheap nowadays, on the second hand market.
I have 2 so I may try it, but I don't have them at hand right now.

 

[MC_RME]

The Digiface USB easily does the job. But it needs a USB connection, won't work stand-alone.

 

[mike7877]

I'll expand: Eventually it'll be for experimenting with active crossovers - a two way with my ATC SCM20 Pro PSL Mk2s, and if that works out well enough I'll try 3 way with my larger stand-mount Polk LSiM703s. The ATC SCM20 Pro PSL Mk2s first because it's simplest - only two drivers, and both drivers are flat for most of an octave above and below 2.1kHz (its passive crossover point for third order Butterworth).

Right now, though, I mainly use the ATCs, and what I want to do is use them optimally with my two Kef Kube 10b subwoofers. Sadly, since I bought them, they probably have only 100 hours on them because I haven't been able to find a point I like.

My DAC right now is Topping A70 Pro Sabre, so what I'd like to do is use the optical output from my RME Babyface Pro to it, applying "LC" (bottom left of picture), at 12dB/oct, and setting the frequency to match my mains. I'm not sure which frequency that is, but I'll find out! Their natural -6dB point is 56Hz...

So my ATC two ways are a sealed design, so applying an additional 12dB/oct rolloff to will make their rolloff 24dB/oct - matching the Kef Kube 10b.
I'll use the "speaker out" of the Babyface Pro for the signal to the subwoofers, and the optical out will be the same signal with the 12dB/oct filter applied. Although the latency of the A70 Pro Sabre is probably not the same as the RME internal DAC, but since this is a subwoofer, it's not critical to be 100% in time. If I notice anything, there is a way to adjust the buffer in the Babyface

 

[Weeb Labs]

I've been looking at the usual suspects from the usual suspects for an adapter to turn the ADAT optical port on my interface into at least two 24/96 SPDIF or ideally four 24/48s, but I haven't had any luck! All I can find is multi-channel ADCs and DACs which connect back through ADAT, nothing that's digital...

My interface is RME Babyface Pro (non-fs).
I've read that RME's driver supports up to three RME devices simultaneously, one has to be master while the other is slave.. I don't know how this can be done if my Babyface only has one ADAT out - if that has to go into another device's input and not a DAC, connecting the two for sync is pretty pointless because there's still just one available optical out (if the second device was another Babyface or interface with only one ADAT as well)

Do I have to buy a DigiFace for this? One of the reasons I got the Babyface 5 years ago was for its ability to expand ADAT to 2x 24/96 and 4x 24/48. Well that day has come, and I'm disappoint! lol
Hopefully not?

If you are still in search of this unit, then I would suggest keeping an eye on my enginerding thread. I will have a board for this purpose ready shortly.

 

[mike7877]

If you are still in search of this unit, then I would suggest keeping an eye on my enginerding thread. I will have a board for this purpose ready shortly.

View attachment 455229View attachment 455230

Looking good!!

I bought myself an RME Digiface USB in the mean time - got me 4x SPDIF up to 192.
I'd still like this for future projects.

 

[rcstevensonaz]

I bought myself an RME Digiface USB in the mean time - got me 4x SPDIF up to 192.

That should work great for you, since your goal is breaking out the audio to separate S/PDIF channels. You can inject both the ADAT source as well as multiple channels from the host computer.

I found out the hard way that the Digiface USB won't help for my situation. My goal is to mix incoming S/PDIF from multiple consumer devices — e.g,. WiiM, WaxWing, DVD Player, Squeezebox. But the Digiface USB doesn't support sample rate correction; and the consumer output devices do not support an external clock source.

 

[rcstevensonaz]

If you are still in search of this unit, then I would suggest keeping an eye on my enginerding thread. I will have a board for this purpose ready shortly.

View attachment 455229View attachment 455230

Any chance you could also create the reverse? Where it is possible to input 4 stereo S/PDIF channels from consumer-grade devices — e.g., WiiM, WaxWing, CD/DVD player, Squeezebox, etc.

In one scenario, I could ensure that all devices are sending at the same sample rate / frequency. But each device would be using its respective internal clock. In this scenario, I would need it to detect that timing to collect samples into a buffer, and then output those samples based on the clock from the board (re-clocking from non-synchronized sources).

The other scenario, the board would apply full sample rate conversation (SRC) on all of the devices, picking up the packets based on whatever frequency and clock timing they are using; then sending the channels out over an ADAT with proper clocking based on the board's clock (whether as primary or from external clock source).

 

[mike7877]

That should work great for you, since your goal is breaking out the audio to separate S/PDIF channels. You can inject both the ADAT source as well as multiple channels from the host computer.

I found out the hard way that the Digiface USB won't help for my situation. My goal is to mix incoming S/PDIF from multiple consumer devices — e.g,. WiiM, WaxWing, DVD Player, Squeezebox. But the Digiface USB doesn't support sample rate correction; and the consumer output devices do not support an external clock source.

Yeah, they all have to be the same sampling rate unfortunately

 

[rcstevensonaz]

Yeah, they all have to be the same sampling rate unfortunately

Sigh... it was an expensive lesson

Turns out what I need (and am hoping for) is a Digiface USB SRC.

That would be a perfect companion to the RME ADI-2 Pro for cases that do not require precisely synchronized audio — e.g. pod casts, home audio, etc. Even more so since it then adds Total Mix functionality to the equation.

 

[Weeb Labs]

Any chance you could also create the reverse? Where it is possible to input 4 stereo S/PDIF channels from consumer-grade devices — e.g., WiiM, WaxWing, CD/DVD player, Squeezebox, etc.

In one scenario, I could ensure that all devices are sending at the same sample rate / frequency. But each device would be using its respective internal clock. In this scenario, I would need it to detect that timing to collect samples into a buffer, and then output those samples based on the clock from the board (re-clocking from non-synchronized sources).

The other scenario, the board would apply full sample rate conversation (SRC) on all of the devices, picking up the packets based on whatever frequency and clock timing they are using; then sending the channels out over an ADAT with proper clocking based on the board's clock (whether as primary or from external clock source).

I will most likely be designing a 4xSPDIF to ADAT board once the current unit is complete but it will be a somewhat more involved project. The ADAT to 4xSPDIF unit is synchronous as the SPDIF transmitters are all driven by the ADAT decoder's master clock, which is either recovered from the ADAT stream or derived from direct word clock input. It's quite a minimalistic implementation, save for a few buffers and inverters.

The 4xSPDIF to ADAT board will need to make use of two ASRCs (probably SRC4184) in order to handle four asynchronous SPDIF input and this will increase both cost and complexity.

 

[rcstevensonaz]

The 4xSPDIF to ADAT board will need to make use of two ASRCs (probably SRC4184) in order to handle four asynchronous SPDIF input and this will increase both cost and complexity.

Even a 1xSPDIF (or 2xSPDIF) to ADAT/SPDIF would be fantastic. Especially if it can take external clock from either a word clock or a separate reference S/PDIF input. And since many of these audio sources are supporting higher sample rates, you are likely limited to only 2 or 4 channels on the ADAT anyway.

Essentially, this is a simple S/PDIF to ADAT+S/PDIF converter/re-clocker that sits in-line between a consumer output device and a professional audio input device that requires the input to be synchronized to it's clock.

For example, in front of an RME Digiface, UCX, UFX, ADI-2 Pro (non-SRC port), etc.

 

[weesch]

I've been looking at the usual suspects from the usual suspects for an adapter to turn the ADAT optical port on my interface into at least two 24/96 SPDIF or ideally four 24/48s, but I haven't had any luck! All I can find is multi-channel ADCs and DACs which connect back through ADAT, nothing that's digital...

My interface is RME Babyface Pro (non-fs).
I've read that RME's driver supports up to three RME devices simultaneously, one has to be master while the other is slave.. I don't know how this can be done if my Babyface only has one ADAT out - if that has to go into another device's input and not a DAC, connecting the two for sync is pretty pointless because there's still just one available optical out (if the second device was another Babyface or interface with only one ADAT as well)

Do I have to buy a DigiFace for this? One of the reasons I got the Babyface 5 years ago was for its ability to expand ADAT to 2x 24/96 and 4x 24/48. Well that day has come, and I'm disappoint! lol
Hopefully not?

hello
if i understand .
the mutec MC 4 will do this

MUTEC – Digital Audio Equipment – High End | Professional Audio - MC4

MUTEC Germany - Manufacturer of Digital Audio and Video Studio Equipment

www.mutec-net.com

mutec is very expensive
you clock the MC 4 with your rme adat masterclock and feed your external gears with MC 4 spdif outs...