Sample accurate digilink interfaces in 2019?

[LDS]

Hey everyone,

What current digilink interfaces are sample accurate to 192s or HD I/O?

Obviously Avid stuff. I assume the Symphony and new Aurora N continue Apogee and Lynx's trend of being sample accurate? Mytek? What about Burl, the Focusrite Red stuff and Antelope Audio HD interfaces?

[JCBigler]

What does sample accurate mean?

[LDS]

Originally Posted by JCBigler

What does sample accurate mean?

HD Native & HDX have preconfigured delay compensation for Digidesign and HD I/O interfaces. When you throw an analogue insert into a mix, the resulting audio should still be sample accurate so that it doesn't cause phase issues with the rest of the mix - think parallel compression with a hardware compressor.

Lynx, for example, mimicked the roundtrip AD/DA latency of the Digidesign 192 with their Aurora's. So it was literally a drop-in replacement for 192's or HD I/Os.

[JCBigler]

So what makes them sample accurate and how do you know if they are?

The Focusrite Red4/8Pre and 16 Line interfaces have a Loop Sync port, in addition to their word clock.

[Mixchump]

I'm running a Merging HORUS interface, and it has many io options, including AES, MADI, and of course Analogue AD/DA. When connected via DigiLink, you can tell it to emulate either HD-Madi, HD-io, or 192-io, which will show up in ProTools as the intended device, and also emulate sample-accurate io delays as well.

[LDS]

Originally Posted by JCBigler

So what makes them sample accurate and how do you know if they are?

The Focusrite Red4/8Pre and 16 Line interfaces have a Loop Sync port, in addition to their word clock.

It isn't really associated with loop sync or word clock. Every interface has an internal latency associated with the AD/DA conversion stages themselves. If that latency in an Avid HD I/O is 17 samples, Pro Tools will automatically compensate for it just like it does for plugin latencies. Lynx made sure their Aurora had that same 17 samples of latency so that Pro Tools treated it no differently.

If a digilink interface has an internal latency of 40 samples, then the audio that returns from your analogue insert will be 23 samples late (40-17=23). You can get it more accurate by fiddling with the I/O offset menu, but even then I think you are limited to an accurate of +/-3 samples because it uses a tenth of a millisecond as the smallest value. I don't actually have any idea what the latency of each device is, so take the figures with a grain of salt. They are just an example of how Pro Tools compensates for latency.

Other DAWs use a ping feature to quickly obtain sample accurate inserts. Pro Tools doesn't... finding a digilink interface that mimics the internal latency of an Avid interface is the quickest way to deal with it. I assume you can test your interface by doing the I/O Offset measurement outlined in the Pro Tools manual. If you are running a HD rig, a result of 0 samples would probably mean you have an interface that is sample accurate to HD I/O (or whatever the device is that appears in your hardware settings).

[LDS]

Originally Posted by Mixchump

I'm running a Merging HORUS interface, and it has many io options, including AES, MADI, and of course Analogue AD/DA. When connected via DigiLink, you can tell it to emulate either HD-Madi, HD-io, or 192-io, which will show up in ProTools as the intended device, and also emulate sample-accurate io delays as well.

Jeepers! That is the way to do it, and great to know.

[JFreak]

It's just a matter of knowing how many samples to compensate (i/o setup); for example, Apogee manuals have charts available -- but sure, it would be easier if someone else did it for you

[LDS]

Originally Posted by JFreak

It's just a matter of knowing how many samples to compensate (i/o setup); for example, Apogee manuals have charts available -- but sure, it would be easier if someone else did it for you

Sure, but that is the equivalent of turning my $6000 HDX system into a $100 Coreaudio interface. Pro Tools HDX by design takes care of it automatically. I just want to know what third party digilink interfaces and their manufacturers have the foresight to maintain the integrity of HDX, in this regard.

The I/O Offset menu was truly sucky in 2010. It's even worse in 2019. I just don't want to have to deal with millisecond offsets and their ever so slightly less-than-perfect maths on an expensive DAW... particularly when DAWs like Reaper, Cubase and Ableton Live can all deal with it quickly and efficiently.

I haven't used Apogee interfaces since the 16X series. I know you needed to enter manual offsets then. Is it still the case with the Symphony and Symphony MKII?

[BScout]

Originally Posted by JFreak

It's just a matter of knowing how many samples to compensate (i/o setup);

msecs vs being compensated by samples
(and having that compensation being correct when changing session sample rates.)

Not the same thing.