Hi Amir and everybody,
Thanks for taking the time to review the UDIO8,
Looking at these measurements, something is quite different from what we're seeing on our side so we'd love to get more info as to the conditions you used to perform the measurement. We just grabbed 5 interfaces now from the stock and they all tested the same. We most likely have a different configuration for the AP or driver used...
See below the Jtest results we're seeing with the UDIO8 vs an APX585 loopback: Quite similar background noise (-180dFS) with peaks at low freq (-140dBFS).
What would be the way to get in touch with you so we nail this? Thanks,
Also, forgot to add but there are indeed ASRC on the digital input. They are here to easily adapt the rate of the input digital stream when not matched to the output rate (or your PC recording rate). i.e. you could have 48k in -> processing on PC - > 192kHz out. A studio application mainly.
To summarise: Two possible paths:
AES-EBU Source -> UDIO-8 input - > SRC4382 chipset performs sample rate conversion - > XMOS - > USB audio
USB - > XMOS -> UDIO8 output (no sample rate conversion)
While SRC have indeed in the past gotten a bad reputation from their limited implementation in early chipset design (limited FIR size), newer versions work better and they do have their benefits in real life applications... Here is a measurement of the input section i.e. APX585 generating the Jtest - > UDIO8 input - > USB audio recording.
Happy to answer general questions and hoping to hear back from how to contact Amir directly.
Tony