PT HDX - Hardware outputs shifting when working at 96 kHz

[sircletus]

I'm experiencing a very strange hardware output behavior in PT when working at or above 96 kHz. I've had this issue for the past year (all of PT 2023, still present with 2024.10). Before I explain precisely what's happening, here's my hardware configuration:

HDX Card Port 1: - HD I/O 16x16 analog --> Apogee DA-16X

HDX Card Port 2: - HD I/O 8x8x8 --> Burl 16ch A to D only

- Entire system is clocked externally to an Antelope OCX.
- I use the DA-16X solely to feed my Aviom system's analog inputs directly from Pro Tools.
- Both HD I/Os are used for analog hardware inserts.
- S/PDIF output on 8x8x8 feeds Trinnov NOVA digitally.
- Burls purely for overdubs.

Outputs of the DA-16X are labeled in I/O setup as "Aviom 1-16."

When working at 48k, ALL inputs and outputs across all four interfaces function as expected.

However, when I work at 96 kHz and higher, something weird happens:

All I/O on the HD I/Os and Burls function properly, but when routing audio to "Aviom 1" through "Aviom 3," no audio comes out of the DA-16X. Then, when sending audio out "Aviom 4," audio comes out of DA-16X channel 1! "Aviom 5" comes out DA-16X 2, and so on. All DA-16X outputs are offset by three!

Just as a test, I did a "Save Copy In..." of a recent 96k session and saved it at 48k. Outputs screwy in original 96k session, just fine in the 48k version.

Strangest thing! Has anyone ever seen this?

[BScout]

That’s correct. ADAT is an S/MUX protocol which means you lose half the channels when you double the sample rate. So at 96k, you only have 4 channels. Channel 1 sends out 1&4 (or, if you send out channel 4, it goes out channel 1). This is normal.

[sircletus]

Originally Posted by BScout

That’s correct. ADAT is an S/MUX protocol which means you lose half the channels when you double the sample rate. So at 96k, you only have 4 channels. Channel 1 sends out 1&4 (or, if you send out channel 4, it goes out channel 1). This is normal.

I'm not using ADAT optical for anything. The DA-16X and Burls are connected via the HD I/Os' expansion ports. ALSO, I'm not losing fully 1/2 of outputs as one would expect with S/MUX. I'm not even losing an even number. I'm losing three.

[sircletus]

Update:

In an effort to eliminate a variable, I swapped one DA-16X out for another.

Same issue:

Digital Outputs 1-3 in PT do not hit the Apogee. Digital outs 4-8 hit Apogee outputs 1-5. Nothing above Digital output 9. So weird.

To be 100% clear: The DA-16X is connected to the HDX card via an HD I/Os expansion port using the old Apogee X-HD card with a mini-Digilink-to-Ol Skool Digilink adapter cable NO OPTICAL.

Probably just an thing with, ya know, using 20 year old DAs with a modern system. But next week I'll be swapping the Apogee with another analog HD I/O to see if its outputs are also shuffling at 96k.

[BScout]

Do you have the DA-16X in advanced mode?
Have you done the firmware update for the Apogee (you open it up and have to do it from the in-built MIDI port you will see)
First firmware update happened around 2006-7 for better Pro Tools operability but a lot of units were never upgraded due to the hassle. There was a second one after that about 3 years later.

Have you tried using them direct and NOT through an HD i/o expansion?

[sircletus]

Originally Posted by BScout

Do you have the DA-16X in advanced mode?
Have you done the firmware update for the Apogee (you open it up and have to do it from the in-built MIDI port you will see)
First firmware update happened around 2006-7 for better Pro Tools operability but a lot of units were never upgraded due to the hassle. There was a second one after that about 3 years later.

Have you tried using them direct and NOT through an HD i/o expansion?

- Yes, tried advanced mode. No change.
- Have not used a standalone DAs. Might test that. Gotta dig out the ol' AES snake.
- Current firmware is 3.0. Most recent, I believe.

It's wild. I'll be really curious to see if the issue persists when I swap it for another HD I/O (on loan) next week. Something tells me the HD I/O will be fine.

These things don't exactly destroy my workflow, but I can be a dog on a bone when it comes to weird gremlins like this.

Thanks for the fresh reply!

[sircletus]

For those curious, I ended up pulling the DA-16X, doing a hardware reset and RE-updating firmware (the firmware installer mercifully allows one to overwrite) and now it works like a champ. I then did the same for my "backup" DA-16X.

Props to Apogee for making a converter that's lasted 20 years. This particular unit is an early double-digit serial number, so almost certainly a first-run box.


EDIT: Nope! I stand corrected. One reboot and everything's back to its previous screwed-up state. Would appear the 3.0 firmware updates have not been "sticking" and the units are still booting into 2.07. *shrug* Oh well. I'll try to track down a used HD I/O and retire the Apogees.

[Eric Lambert]

Originally Posted by sircletus

I'll try to track down a used HD I/O and retire the Apogees.

Do you want one? Because I have one with the analog card (for a total of 16 analog ins) and the quieter fan installed. I'm not using it so it could be for sale.