For a few weeks now I call the T1 and the headphone amplifier A1 from Beyerdynamic my own. Since the phone was delivered a few days beforehand, I first connected it directly to my CD player. The listening was all in all no more than mediocrity. Even hearing a Project KH amplifier not led to the hoped-for improvement, though compared with the direct connection to the CD player, an increase was evident. As then arrived the Beyerdynamic KH amplifier and I used to hear the combination, a completely different picture emerged. Resolution, detail, dynamic, everything was suddenly much better. As music I've pretty much used all Querbeet (from Abba to Zappa, classical, jazz, pop and rock) and it has done with any style of a lot of fun. Would I personally buy the headphones again and / or recommend: A clear yes and no; Yes, if you are prepared to order and the Beyerdynamic amplifier, No if selbiges is not the case.