No complaints so far. As for the amplifier itself, it makes my headphones sing! Very transparent, dynamic, and engaging without ever being harsh. It is fantastic, and the Burson team definitely did a great job on this amp. I love it! The LED lights, however, are too bright for me. I wish there was an option to turn the display brightness down. Also, the blue LED standby light, I suggest, should be a different color; the blue stands out so much in the dark.