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Old 04-02-2019, 07:21 PM   #30
Nana
Human being with feelings
 
Join Date: Jul 2015
Posts: 58
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NO!

SR should always be "locked" to produce crackle-free and correctly tuned audio.
If it is not locked when clock source is set to "internal", there is a damage in the internal clock source!

With an external studio clock / word clock it is easy to demonstrate what happens if the clock is skewed or distuned: The lock turns off and the card quickly speeds up or slows down until SR gets locked again. This takes longer the further away the word clock rate is from the set clock range and even ends with the audio stopping completely, if it is too far off. If the clock line is not properly terminated, there will be jitter and reflections on the line and the "locked" my never turn on. In such cases, the SR clock may be freewheeling on the upper band center of the selected clock range (48k, 96k,192k), but the audio will not be exactly in tune and sync.


When feeding digital signal (S/PDIF)is not synced to a central word clock and the E-MU card is not a master clock source for the feeding device, the clock source should ne set to that input to ensure every single word is correctly captured. If the digital source is not stable and not sync with the card, crackles or distortion will result. After capturing the recording, it makes sense to then set the clock source to internal.
If all devices are synced via word clock or if the E-MU card is the master, then it is not necessary to switch clock source, just keep it on the central word clock(or the internal master clock, if this is output as master to the external devices). In every scenario, the SR should be "locked".

Last edited by Nana; 04-02-2019 at 07:48 PM.
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