Auto standby does nothing in regard to audio. It just turns off unit when input is no longer active (as in, you suspend or close PC)
I already explained what is happening and I'm 99% confident this is the case after lots of testing.
USB is needlessly resampling any input it receives. Normal (sane) behavior should be that resampling is done when sample of audio changes. You don't need to resample from 44.1 to 44.1 if DAC is already operating in 44.1, however you do need to resample 44.1 to 192 if input changes to 192. This is exactly what can be observed with toslink connection, switch from WASAPI mode foobar to youtube = click because 44.1 to 192. Switch from one 44.1 song to another 44.1 song in WASAPI foobar = no click because no resampling done.
USB and TOSLINK is not operating the same on this unit, which is pretty clear indication that something is very wrong.
By the way I wonder if improved perfomance of USB vs spdif observed in tests is somehow related to this.
I don't think the word 'resampling' is the right to use here, which is why I was getting confused about the exact nature of the issues owners have talked about here.
Resampling in audio terms means conversion of one sample rate to another either by software or hardware methods: "
Resampling or the more specific terms upsampling or downsampling usually mean sample rate conversion only. Low-quality
resampling algorithms, whether upsampling or downsampling, can introduce artifacts which are clearly audible in the
resampled audio file."
Now, I'm not certain exactly what's going on here with this issue, but it sounds like the DAC is unnecessarily re-initialising each time it receives data or there is a break in the data (seek, pause, etc). As someone else said, ideally the only time this change of sample rate 'click' should occur is when audio data is received that has a different sample rate to the last data sent to the DAC.
This could be caused by the hardware, the software, the way the hardware and software are interfacing with each other and if there is any other interruptions to the data stream from other drivers/software. It's all guesswork at this stage as 1) I haven't received my DX3 Pro yet and 2) I'm not a software engineer.
Anyone with this issue should be contacting Topping so that they work on a fix as soon as possible.