I own this.

I’m guessing the author doesn’t have this issue, but the model sold in the US has a volume limiter limit on them. My daily headphones aren’t easy to drive, so this was a concern I have that many other people might not care about.

I ended up having to import mine to get a device that doesn’t have this enforced.

Edit: Sorry I was clumsy with my words. It’s a limit on volume, since it’s an option for high gain.