The SMSL M2 I use to connect a pair of headphones AKG K701 to a MacBook Air or Mac mini, and it fits in perfectly with silver visually devices from Apple. Compared to the connection of the air of effortless M2 and there are higher volume sounds possible. Only with an older AKG K240 with 600 ohm impedance of the M2 comes to its limits, which remains relatively quiet. Headphones with 600 Ohm are but become rare anyway. Noise I could not find, and the M2 sounds completely neutral, without increase or decrease, which would also be quite unusual for a device of this kind any pitches. The only drawback: The first copy was out at the line-out jack still a short time a channel, I suspect a defective contact spring and was returned. As a small flaw I feel that the M2 computer operating system reports two input sources, which are lack of appropriate jacks not exist.
