Lynx Aurora 16 trouble at 192kHz?

[jte221]

Dear Duc Forum,

I've encountered a Lynx Aurora 16 interface that is having trouble running at 192kHz with Pro Tools or any audio application. I'm writing to ask if anyone else has seen this, knows a solution or can say "my Aurora definitely works at 192k!" I'm working with Lynx about the issue but I wanted to see if any other users might have experience with this problem.

The full system is a 2011 Mac Pro with OS 10.9.5 running Pro Tools 11.3.1.370 with an HDX card that is connected to an LT-HD card in the Lynx Aurora 16. Whenever a 192k session is opened up the interface plays full scale white noise on all channels and seems to loose communication with the computer and cause some preference files to be corrupted. The only solution is to delete the Pro Tools preferences, restart and open a session at another sample rate.

We've done a lot of troubleshooting trying to isolate the problem. As a summary: On all other sample rates the interface works fine. We've tried swapping the Lynx interface with an Avid HD I/O and saw the problem go away We've seen the problem show up when connecting the interface to other systems. This would all suggest that the problem is with the interface (probably the LT-HD card) but the problem remained when we swapped the LT-HD card and yet when sent the interface to Lynx, they couldn't replicate the problem.

We've also tried:
Updating the Aurora Firmware.
Changing to Mac OS 10.10 and Pro Tools Version 11.3.2 but the problem remains.
Running the interface in 16 and 32 channel modes - problem remains.
Sending the analog input signal to the analog output signal on the Lynx while running at 192k - this works fine.
Sending a 192k AES signal to the interface - the interface handles this just fine as well.

Any thoughts would be much appreciated!

[JuanPC]

if the LT-HD card is OK...
the problem could be the Aurora... or how you plugin the card inside.
or the HDX card...
or the Digilink cable.

you need to test that Aurora+LTHD in other HDX/PC that has aurora and works at 192khz...
but first, test another cable, veryfy no pins are bent..
then another HDX card,
then other PC.

[jte221]

Thanks Juan!

We did a test swapping out the Aurora interface with an Avid HD I/O leaving the cabling and cards untouched and saw the Avid box working perfectly at all sample rates.

Then we did another test in different studio hooking up the Aurora interface to another working Pro Tools HDX system and the interface had the same problems at 192 in the other studio so we're fairly confident the problem is not a bad HDX card or digilink cable.

[jte221]

One big clue seems to be in the results of the Digitest we ran on this interface. As a control for our experiment we ran Digitest on a working Avid HD I/O interface using the same cabling and HDX card and found that it passed the Digitest.

Then, when we ran Digitest on the Lynx Aurora we got the following results:

Peripheral Loopback Test Connector 1 Pri ---- Failed - Data Missing or invalid: Group 1 Group 2
Peripheral Loopback Test Connector 1 Sec ---- Failed - Data Missing or invalid: Group 1 Group 2
SDI 0 PIO Floating Point Test ---- Failed
SDI 0 PIO Loop Single Chan ---- Failed
SDI 0 PIO TDM Loop In B-A ---- Failed
SDI 0 PIO TDM Loop Int B-A 192k ---- Failed
SDI 0 PIO TDM Loop Int B-A 96k ---- Failed
SDI 0 TDM PIO Loop Int B-A ---- Failed
SDI 0 TDM PIO Loop Int B-A 192k ---- Failed
SDI 0 TDM PIO Loop Int B-A 96k ---- Failed
SDI 0 PIO Floating Point Test ---- Failed

Lynx says they would expect their interface to fail the first two Peripheral Loopback Tests but the other failures seem to indicate there could be a problem with the HDX card or the connection between the interface and the card.

Is anyone familiar enough with these Digitest results to know what kind of problem they indicate?

[pinosmuse]

Hi jte22,

I recently encountered the exact same failures in digitest.
What was the cause in your situation?

Thnx

[jte221]

Hi Pinosmuse,

I wish I could offer more help - though I can see I was deep in the weeds of this problem only a year ago, I can't offer much of a detailed solution or summary at this point.

Essentially this problem appeared as one user of our studio was interested in working at 192kHz, our team did what we could to get to the bottom of the problems with this interface and Lynx went above and beyond in every respect to help us (including long and frequent telephone support, shipping factory tested units and cards to help isolate the problem, etc.) but ultimately this interface would not work for us at 192kHz in any long term stable way.

I can't say if our unique combination of hardware and software contributed to the problem, or if this problem has been corrected in newer revisions of the product but for us the ultimate solution seems to have been recording at lower sample rates.

I don't mean to be critical of Lynx - I like the flexible Avid HDX/Firewire/MADI interface options on the Aurora, and it's sound quality, form factor and price are perfect for 99% of our needs. That being said, the amount of time invested in trying to get this box to work at 192 was not well spent and for your time and sanity I would recommend looking into other interfaces if you're spending too long on this problem and truly need a high sample rate.

[jte221]

Of course, Pinosmuse or anyone else, if you find a solution to this I would be curious to hear about it!!

As a general note (probably not relevant to these 192kHz issues) most problems I've seen with our Aurora that uses an LT-HD card to connect with an Avid PCI card are solved by cleaning and re-seating the digilink cable. We've had the interface crash and play full scale digital noise etc and the culprit was slightly loose/dirty cable.

For full precaution I would re-seat the cable with the computer and interface powered down and a bit of contact cleaner should help (Deoxit D5 then Deoxit G5 probably). Long term it's wise to use some solid strain relief on that digilink cable as the connectors are very delicate.

Also check that the interface and LT card's firmware are up to date - the Lynx application is a bit clunky and sends data via MIDI protocol but it ultimately works fine.

[pinosmuse]

Hi jte22,

Thanks for your response. Things worked for me pretty properly before.
Although I also hardly ever use the 192KHz rate either.

Lately I changed a few things in my setup.
-Changed my old 192 to a Lynx Aurora. I already used 2 aurora's, so I don't guess that that's the problem.
-I upgrade to PT12.7. Since you had the same problems a year ago. I don't guess that's the problem either.
-I upgraded my videocard. From a pretty basic one to a card that uses the second power connection from the Mac Pro. I'll try swapping the old card back in. See if that helps.

grtz