AndrewKirkland

Inspired
I just want to ask for clarification of a few things regarding clocking. It seems I am forced to use the internal clock on the axe FX with an AES connection. I have my interface set to 48khz internal clock with the Axe on auto and it seems like there is no issue. I can also slave the interface to digital in at 48khz. However slaving the axe FX won't work. Apparently when using analog in as a source (which I must do to see input signal from my guitar) makes the axe use its own internal clock. When I select AES for source, and then AES again for word clock there is no signal. If I choose analog in as source and then try to use AES for word clock the no input message comes up, apparently defaulting the clock to the axe internal. However I do notice a change in sound when changing the word clock to AES instead of auto. This causes a slightly thicker sound after the message pops up and goes off.

Sorry for a long technical post, just curious how I should approach this. Everything sounds great. I just one day had some slight crackle on some presets and thought the clocking was causing it, but it was just having too bright of settings/presence and also too bright of eq in my DAW.
 
A. When main input source = SPDIF/AES:

Axe-FX cannot use its own internal clock and derives clock from incoming digital signal. Set your other interface for internal clock in this scenario.

B. When main input source = Analog input 1:

Axe-FX can use internal clock or sync to incoming digital signal, depending on "word clock" parameter setting. Your choice for that parameter determines what the proper clock source for your other interface should be. (Exactly one device should be clock source, not two or zero.)
 
Thanks for the tip, seems like in my set up with analog in the auto setting would mean using the axe FX clock, and the aes setting would mean using my interface clock. I appreciate your help! Thank you taking the time to explain!
 
Just thought I post results of my clocking. So with the axe as the master everything was more present and very dynamic sounding/very alive. With my interface(metric Halo) as the master clock the sound was very smooth and detailed, but maybe a little too much smoothing so the dynamics we're not the same. When using both as a master (using bi directional AES) there are occasionally slight pops/crackles not present on the other ways I set up, and the tone is somewhere in between the smooth metric Halo and the dynamic vibrant axe FX master. Not sure why these differences exist, maybe it has to do with the conversion/sampling. I'd be curious to hear if anyone has tried this and heard different tones.
 
It’s worth checking your CPU usage on the Axe with the selected preset - the crackling may be due to this, rather than it being a clocking issue. Anything above mid eighty percent can cause the behaviour you’re describing, so you may need to simplify the preset.
 
I think it's unlikely that switching clock source was changing tone or dynamics.

Crackling isn't surprising with both devices set to be master. There's no actual sync then.
 
Yeah the noise only occurs when there is no master clock and both devices are at 48khz. Doesn't happen when one is a master clock source. When the axe is the master the tone is different from when it is slaved. Subtle but still noticeable.
 
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