Seems like great value for £98, for a Class A valve headphone amp, with high-quality construction and a proper, heavy-duty linear PSU: https://www.ebay.co.uk/itm/274022984645
I've been looking for something like this for a while [a headphone amp that should offer very high-SPPV, and that could potentially be a 'giant killer], so we'll see what it's like in due course!
Marco.