Page 1 of 1

Tempo changes with Sample Frequency

Posted: Wed May 11, 2016 7:34 am
by Cosmos275
Hi all, I've used DP for years, but not very complicated.

I'm not trying to record in 24/96 with a drum machine.

I got the thing sync'd which is great.

The problem is when I change the sample frequency to 96kHz, the tempo cuts in half. It actually seems to start ok, but in a fraction of a second, slows to half. If I change the rate to 192, the tempo cuts even more. This is visible in the tempo counter window. Also, the drum machine, which is only being sent MIDI (nothing the other way) slows accordingly.

Any ideas? Thanks

Re: Tempo changes with Sample Frequency

Posted: Wed May 11, 2016 7:40 am
by Cosmos275
To clarify, the drum machine takes a half second to slow down, DP counts off right away at half the tempo. DP says "120" but you can see it's actually going at 60

Re: Tempo changes with Sample Frequency

Posted: Wed May 11, 2016 8:55 am
by stubbsonic
It sounds like you are changing the clock rate in one place, but some other part of your system is not changing it's clock.

Try going to the Setup Menu/Configure Audio System.../Configure Hardware Driver...

There you will set the rate of the driver. If your hardware driver doesn't offer a 96K rate, DP will behave as you describe.

In my control panel, I have a little section that shows that the project's sample rate has changed, and it shows the bit-depth (where I could change it from 16/24/32-float).

Is that where you are making these changes?

In my rig, my interface is my clock master. What is your audio interface?

Re: Tempo changes with Sample Frequency

Posted: Wed May 11, 2016 10:36 am
by Cosmos275
I'm making the change on the DP7 transport bar. My interface in a MOTU ultralite mk3. It is probably set at 44.1/16. I'll go check. Thanks!

Re: Tempo changes with Sample Frequency

Posted: Thu May 12, 2016 6:29 am
by Cosmos275
Mr. Stubs, you win the prize! I set the mk3 interface to 96, and all is well. Then, I tried playing a 44.1 project. I noticed the mk3 automatically changed back to 44. Then I went back the the 96 project. It was acting a little funny, but I restarted DP and it was all good. So, I think maybe all I needed to do was restart DP when switching sample rates. In any case, it's working and you were correct on where to look. Thanks!

Re: Tempo changes with Sample Frequency

Posted: Thu May 12, 2016 9:45 am
by stubbsonic
Pheew! Glad you got it working. Must be some link that is supposed to change the rate in the driver & hardware that is not always working as it should. Sometimes a work-around is the best you can hope for. If you let MOTU know there is a glitch, they might be able to sort it in the next driver update.

Re: Tempo changes with Sample Frequency

Posted: Thu May 12, 2016 1:30 pm
by Cosmos275
I did start a ticket with Motu. They responded with a form letter about "glitches" and invited me to spend a few hours building my computer back up from scratch.. no thanks. I'm exaggerating a little, but whatever. Restarting DP is easy. The iMac I'm working from is a dinosaur, so I'm just happy it's still kickin. Thanks for the help!