Focusrite Saffire 40: Problems at 96kHz

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Frank Carvalho
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Posts: 363
Joined: Sat Nov 17, 2012 3:36 pm

Focusrite Saffire 40: Problems at 96kHz

Post by Frank Carvalho »

Hi

I made this comment under the other headline and got no response. So I guess I should try again under a more fitting headline:

I tested my friends FSP 40 today using the tweaks above. It works prefectly when running at 48kHz. I can use a buffer size of 64 samples, and run with a latency of 1.3 ms for tracking. Playback works perfectly.

However, I have problems getting things to work at 96kHz. I can get jackd to start, buffer size 128, and it presents all the firefire ins and outs as it should. Connecting Ardour appears to work, as it is able to see input and record input, showing waveforms etc. But there is no playback sound. The connections are correct, there are output levels at Ardours master out, and master out is connected to the firewire out channels. But no sound.
I tried playing back a file directly to the firewire output with Audacity, and still nothing.
I have compared the setup to the 48kHz project, and all is identical, except the 48kHz still plays back correctly.
I have tried to increase buffer size in JACK, and still no playback sound.
I also had a look at the settings in the ffado-mixer, and they are identical too, apart from the sample rate.
Then I tried to loop a short piece of sound for a while, and in Ardour I can see that the cursor sometimes stops and moves in short skips, as if the transport doesn't work correctly all the time. When this happens I can hear some chirping fragments of the recorded sound.

Any ideas? It sounds like a syncing problem to me, but I don't know where to look for further cues. The FSP40 is currently set to internal clock. Should I use an external SPDIF from the computers other sound card (a 2496), or what do you suggest?

/Frank
Vox, Selmer, Yamaha and Leslie amplifiers. Rickenbacker, Epiphone, Ibanez, Washburn, Segovia, Yamaha and Fender guitars. Hammond, Moog, Roland, Korg, Yamaha, Crumar, Ensoniq and Mellotron keyboards. Xubuntu+KXStudio recording setup.
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