Originally Posted by Almoxil
I chose to buy the PA2V2 instead, and will use it with my CK7s and PortaPros.
If you intend to use the PA2V2 with the D2, you'd be in for an unpleasant surprise.
I've been testing all the inefficient high-impedance headphones in the stores, equipped with my D2 and PA2V2. Sennheiser HD600/650 (300 Ohm), Beyerdynamic DT880/990 (250 Ohm), etc... they all sounded better
straight out of the D2's 74mW amp than over the PA2V2's 200mW amp.
Of course the PA2V2 could drive them to somewhat higher volume levels - but the sound quality suffered quite noticeably. All of these phones sound muddier, more congested, with less soundstage over the PA2V2.
A low-budget portable amp like the PA2V2 might be useful to spice up low-quality players or computer sound cards, but for a high-quality player like the D2 it provides no improvement at all, not for 300 Ohm phones - and especially not for low impedance cans like the CK7 or PortaPro.