Channel count changed restart Pro Tools

[justinhill]

If like me you have an interface with ADAT i/o on it, it will present more i/os at 48K and below than at higher rates.

So, if I close an 88.2K session and open a 48K session, Pro Tools says "i/o channel count has changed, restart Pro Tools". Which is annoying if I'm jumping back and forth between two projects.

But what I really can't understand is why if I close the 88.2 session, shut down the computer, go home, come back after the weekend, turn on the computer, double-click the 48K session... does it launch Pro Tools, open the session, dither about - and THEN tell me I have to quit Pro Tools, which I've only just launched!

(And I don't even use the ADAT i/o)

[BScout]

Because the last session opened is what PT's mix engine is set to when you start Pro Tools. Which is wrong for 48k in this case.

[Darryl Ramm]

If you are not using ADAT you can probably go into Setup> I/O and delete those paths and save those settings and use for all sessions.

[BScout]

Originally Posted by Darryl Ramm

If you are not using ADAT you can probably go into Setup> I/O and delete those paths and save those settings and use for all sessions.

That won't change the restart issue. If the hardware presents with different channel counts (via driver), this will happen regardless of I/O usage. And the Presonus Quantum has a very basic driver (verses some better hardware that allows channel hiding from the driver)

[Darryl Ramm]

Thanks, was a distant memory so I was not entirely sure, and part of this is that the I/O settings have to change after Pro Tools has the session open. Which takes a sample rate change with a driver with that behavior.

With my RME interfaces I don't ever see this since the drivers are smart (or dumb?) enough not to change apparent ADAT/MADI/etc. I/O port availability as the sample rate changes. (can't recall if they do in mainstream kext versions but I'm running beta user space drivers for now).

The only way with my RME interfaces I can force a driver to show a different I/O config is say run class compliant USB 2, or USB 2, or USB 3.1 (or Thunderbolt) to the UFX+. Those steps change I/O availability but those changes happen before the session is open so don't have this affect.

[justinhill]

Thanks all for your replies. I guess I wasn't so much trying to find a resolution or explanation for this as just having a rant... It's unfortunate that I'm working on two projects at the same time that have different sample rates and keep having to flip between them. It's not usual for me.

Nice to hear that my Quantum 4848 has a 'very basic driver'... It was the only thunderbolt interface I could find that had 32 analogue line i/os. I must say I would much rather have had S/PDIF i/o on it than ADAT anyway but there you go... In fact I would rather have HDX and a couple of 16x16 interfaces but until I win the lottery...