It's been about 5 years that I have this amp and headset fulfills its function. My and my HD600DT911 & 931 are a bit of a punch when the plug on it. The sound is quite dynamic and defined, the stamps are signed REGA (rather hot), and the output power is much greater than most headphone outputs encountered (pc, cd player, ...).
The price of this product is correct, although it remains more expensive than other amps headset 50 to € 150, remember that you buy a branded product that is manufactured.
There are better products than the Rega Ear but also at what price, and others almost as good but with such fabrication.
I put him eight for good manufacturing and sound qualities.