DIO-8 cards: HDR via TDIF / DAW via ADAT choice possible?

[Y-my-R]

I'm aware of that Cranborne unit, was (and am still) considering to get one, and the way I had planned to implement it was to have a DIO-8 (or OPT-8) card in the Alt I/O slot of the D8B, and have that connected to my digital patchbay (M-Audio Digitpatch 6x12 - it has 6 optical digital port-pairs that work for ADAT (and/or S/PDIF), plus another 6 RCA jack pairs that work for S/PDIF only), and would then have the Cranborne unit go to the digital patchbay as well.

So, if set that way, I could have the Cranborne unit use the 8 Alt I/O channels, over the detour of the DIGITAL Patchbay.

This leaves another 4 optical pairs on the digital Patchbay for other ADAT optical devices, so I can still get other (sets of 8-channels of) signals in and out of the D8B via ADAT and w/o changing wires.

I was thinking to get a nice 8-channel pre with ADAT out, and add that to the Alt I/O. If I put that on the digital Patchbay as well, I would have a choice to use the nice Pres during tracking, but then tie in the 500 Series modules in the Cranborne, when it’s time to add effects after recording… or start mixing.

...and I'd put the Line inputs/outputs of the 8-channel pre-unit on my analog patchbay, of course, so I could tie in outboard gear via the ANALOG patchbay and the 8-channel Pre&AD/DA unit.

Neither, a nice 8 channel pre, nor a Cranborne 500 Series unit with ADAT out were on the top of my priority list, lately, but once I get them, the above is how I’d hook it all up, to get maximum flexibility out of my setup without wiring changes

…oh, and I have to try this, still, but since the D8B allows to set ADAT or TDIF for it’s inputs and outputs separately, I guess this should mean that I should be able to transfer 24 digital channels at a time between the DAW and the HDR, by playing back on one end, and recording on all tracks on the other.
At least in theory, the recording should be identical to the source, if everything is set to unity gain, everywhere in the digital signal path. (I don’t trust that though, and know that it will mess with the integrity of those little zeros and ones… but nobody would ever hear the difference, I think… I wonder if there would be measurable jitter. Aaaaanyway…)

What a nerdy hobby this is, hahaha...

[Y-my-R]

Quick update:

I tried if I can have the DAW, D8B and HDR synced to the same word clock and time-code, and if I can then send audio from the DAW via ADAT into the D8B on the Tape return cards, and back out through the same Tape I/O cards to the HDR via TDIF and record it there.

This worked just fine and sounded identical to me. Of course I had to patch those tape return channels back to the tape outputs on the D8B, and got a warning that this could cause a feedback loop... but since the signal isn't going back to ADAT which would cause the feedback loop, but to TDIF instead, OK'ing this setting caused no problems and no feedback.

I then tried the reverse - sending audio from the HDR into the D8B via TDIF on the Tape I/O cards, and back out from the D8B via the same Tape I/O cards, but through the ADAT port and into the DAW - then I recorded those ADAT inputs from the DAW again.

Same thing, worked fine and sounded clean/identical to me.

I could only do this for 8 tracks at a time so far, since I only got the first 8 channels connected via TDIF on the HDR so far... but there is no reason why it would do anything differently for the remaining 16-channels.

So, this means that if I need to transfer audio between the DAW and HDR (or vice versa), I could do so in real-time by playing on one end and routing signals out the 24 digital outputs (i.e. ADAT or TDIF), and recording all 24 tracks again via digital inputs on the other end (i.e. TDIF or ADAT).

Again, in theory there should be no quality loss, but most likely the digital signal is modified at least to some degree (i.e. likely not "bit-perfect"), and any jitter happening to the signal during the "transfer" could theoretically also make the quality worse.

In practical use, however, I don't think it will make a difference and I don't think anybody would ever be able to tell. I'll experiment with it when I have the first "real world" case where I'd like to mix something via the D8B/HDR combo that I prepared in the DAW, but it might still be a little while until then.

I have to say, though... the D8B never fails to impress me. This is pretty cool sh*t, IMO!!

[doktor1360]

Continuing this thread a bit (constructively of course), here's a list of links with the hardware I've located which I feel should do all the infrastucture 'work':

Cranborne 500R8 - 500 Series Channel Strip & ADAT interface
https://www.cranborne-audio.com/500r8

Amazon TOS-Link Switches - provide 2 into 1 switchable ADAT channel
https://www.amazon.com/dp/B07L58WMQW/?coliid=I337K5DFBJ80PQ&colid=3O58OVNEU05KU&psc=1&ref_=lv_ov_lig_dp_it

Amazon TOS-Link Splitters - split and route the ADAT audio signal to each endpoint (no switching)
https://www.amazon.com/BlueRigger-Toslink-Digital-Optical-Splitter/dp/B0749G18PF/ref=psdc_3236443011_t2_B07L58WMQW
or
https://www.amazon.com/Optical-Splitter-Converter-24K-Connector-Playstation/dp/B08Y5YYN49/ref=sr_1_9?crid=13T5S75H9YT2O&dchild=1&keywords=toslink+splitter+1+in+2+out&qid=1626278620&s=electronics&sprefix=toslink+spli%2Celectronics%2C177&sr=1-9

Attached this .PNG for veracity - anyone have any input and/or constructive criticism? Just throwing this over the wall to get some other eyeballs on this logical layout. Did I overlook anything or not think this completely thru?!? I'd really love to hear any/all input y'all have.

Apologies for wasting anyone's bandwidth here... thanx in advance!

[Y-my-R]

My understanding of that Cranborne unit is, that it has two ADAT optical ports to do S/MUX.

So, each optical ADAT port can do up to 8 channels of audio at up to 48 kHz, or 4 channels at up to 96 kHz, or 2 channels at 192 kHz by "S/MUX-ing" the streams (splitting up the data for a single audio stream over two or more digital audio channels).

If you want to do 8 channels at 96 kHz, you need to have two pairs of ADAT connectors (two optical inputs, two optical outputs). I think that's why the Cranborne unit has two ADAT pairs on it, and it likely CANNOT use it to do 16 channels of Audio at up to 48 kHz instead (but I'd have to read up on it some more to be certain... would be odd to have the 16 channel architecture throughout the whole unit, and then only make it accessible via ADAT and not analog, though).

That's also how the Apollo 8 does it, btw. It only has the capability of getting 8 channels in/out via ADAT (even though it has two sets of ADAT ports), but if you want to do anything higher than 48 kHz for 8 channels, you need to use all 4 ADAT connectors to get those 8 channels in and out (...or 4 channels at 192 kHz over 2 ADAT input and/or 2 ADAT output ports).
Otherwise, at sample rates up to 48 kHz, the Apollo 8 just mirrors the ADAT Out 1 on ADAT out 2, and doesn't use the 2nd ADAT input.

I have an Apollo 8 and use it with the D8B for 8 channels at 44.1 kHz, and in parallel, use a PreSonus Quantum interface, that can actually use it's two ADAT optical pairs for 16 audio channels at up to 48 kHz. Between the two, I get 24 channels of digital I/O to/from the D8B.

Of course the D8B can't handle sample rates higher than 48 kHz, so it really only makes sense to connect one of the ADAT pairs from the Cranborne unit to it. For the HDR, there's a special I/O card that can do 96 kHz, but if you're using regular DIO-8 cards or ADAT I/O cards (forgot the proper name right now), then it also only does 48 kHz max.

My personal approach would be, to have the 8 channels (max) you can get digitally from the Cranborne unit connected to the Alt I/O card (via a digital patchbay as previously described, to get other choices, such as a good 8-channel pre and D/A converter like for example, an Audient ASP 880), since the Tape I/Os are already occupied to send 24 channels back and forth between the DAW (or HDR via TDIF) for me.

If you need less than 24 channels from the HDR (or DAW), I guess you could put the Cranborne unit on the Tape I/O cards instead, but personally, I do need the full 24 channels back from the DAW at mixdown, and would probably also like to use some of the 500 Series cards in the Cranborne digitally as well at that time. So, for me personally, the only viable option is to add the Cranborne unit to the Alt I/O slot (while going over a patchbay, so it's not the ONLY thing on that port).

Anyway... different strokes... but that's what I'd prefer for my own setup.

Cheers,
Roland

[Y-my-R]

Quick update on the topic in the subject line:

IT WORKS!

I finally got a set of 3 affordable digital TDIF DB25 cables (Cable Up PW88D - Ametron in Hollywood had a few left for $20 a pop), and hooked them up between the D8B and HDR via DIO8 cards that are installed in both.

I initially had lots of problems when I tried, that gave odd level meters on channels where there should have been no audio - even across different 8 channel banks... and no usable Audio via TDIF or ADAT, both.
The problem was apparently, that I had DIO8 cards with different firmware versions installed, and per the database, the sending and receiving DIO8 cards always need to use the same firmware version.
(I had misunderstood this previously, thinking that the cards in the same unit need to be of the same firmware version - but it's apparently the sending/receiving cards that need to match. But making sure they ALL run the LATEST firmware version is always best, of course)

Luckily I DO have 6x DIO8 cards with the latest firmware version (2.1), and installed them in the HDR and D8B. After this, everything worked perfectly, and I can now choose in the D8B's Setup/Digital I/O window, if I want the TDIF or ADAT inputs or outputs to be used for each bank of 8 Tape Channels.

Since I made sure that all DIO8 cards are using the 2.1 firmware, I also haven't had any more weird startup issues with my D8B. At least so far... but I don't want to jinx it.

I also got rid of my MIDI merger/splitter setup that I had used to sync it all together, before. As it turns out, I can just set my old Emagic Unitor 8 to "patch mode" (i.e. standalone w/o a computer) to achieve all the necessary MIDI routing for when I want to work with the D8B/HDR without the DAW computer turned on (HDR generates time code)... or just have the Unitor be an interface to the DAW computer, and send out MTC to the D8B and HDR (chases time code), to have all 3 run in sync.

If they all run in sync, it's possible to do stuff like setting the ADAT input on the D8B, to directly pass the signal out to the TDIF without running through the desk, for the purpose of transferring 24 channels digitally in real-time between the DAW and the HDR. The same of course also works in the other direction.

I transferred 24 channels simultaneously several times now without problems, so it's no longer a theory but it really works reliably for me, here (in an earlier post, it was only 8 channels at a time because I only had one TDIF cable/adapter - now, it's 24, after troubleshooting the firmware version issue mentioned earlier).

I'm really thrilled with this sort of "dual" setup, that allows me to run a traditional workflow via the D8B/HDR and outboard gear, but that allows me to seamlessly integrate my DAW computer (aka a "modern" workflow) in banks of 8, by just switching where the D8B gets its signal from (or sends it to).
(Besides, I can still just run the DAW computer and monitor via a Mackie Big Knob, without even turning the D8B on).

I feel like this is a true "best of both worlds" setup, that allows for the proven traditional old-school split mixer & tape machine workflow, but ALSO for a DAW based workflow. It's not either/or. It's both... whichever approach you want to take at any given time.

It's awesome!