I hope it's an improvement over Truthear Zero in terms of technical ability at somewhat the same price range.

Good read, upvote for listening to IU💜

I am not entirely sure what it does, but it feels like turning on "linear scale" spreads volume (over 100 levels) much more evenly if that makes sense.

For example:

When I use apple dongle for my iems, I usually gets comfortable volume around 3-5 steps of volume level. But increase in one more step of volume level from this makes it painfully loud without linear scale turned on.

With linear scale turned on I usually end up in comfortable volume around 60-70 steps. And increase in each steps of volume level is not making it painfully loud.

So I get much more flexibility in adjusting volume to taste with linear scale on.

You could turn on "linear scale" option to get much more flexibility in changing volume levels.

Audio Hardware >> Direct USB Access >> Volume Control >> Linear Scale