44.1 or 88.2? What is happening in unfold?

New to all of this, and seeking some clarification. Please see image below - if the “source” is 44.1, what is happening in the “unfold” to 88.2? Am I hearing hi-res, or upsampled?

You are hearing the first unfold of MQA feeding your DAC which I assume in not MQA aware. So you have an 88.2/24 file to enjoy

It’s a Linn DSM, so is MQA capable as a renderer.

But it’s still not clear to me how this works if source is still at CD resolution.

You need to read up on MQA but the first unfold is giving you an 88.2 file. That’s it. This extra information was previously stored below the noise floor.

A 16 bit MQA can mean multiple things:

Sadly, there’s no way to see which is which based on the file format or signal path. MQA should’ve given these different labels…

Here’s my take - it’s cd res, upsampled to 88.2. But not a native hi-res file.

That’s not true at all, it as an MQA file unfolded to 88.2, that’s different to upsampling. My speakers upsample and Apodise, but that’s not MQA

All MQA is decoded to 2x sample rate (MQA Core) prior to rendering. From a terminology perspective, I think that MQA would say that the 44.1k is encapsulated at 88.2k and then packed to 44.1k. And then unfolded again during the MQA decode.

It’s unlikely to be up-sampling in the conventional “apply 2x up-sampling filter” sense, but I could be wrong. However, I’m not going to speculate how this is done or what is involved.