The Senn PX100 is a great headphone.
Also on sale right now: the HD600 for $300... (insane price for Canada)
The Amperior is really very close to the HD25, but given the lower impedance it'll behave differently depending on the amplifier. In general, I'd say it's cleaner up top but slightly looser in the midbass region, with a decent amp negating the difference in the bass.
Both a "sale" and "wanted" post today for friends of mine...
1) I have a friend looking to sell a HE-400 (not the newer 400i) and Magni/Modi. Anyone interested?
2) Another friend is looking for a Xmas headphone gift for her sister. Requirements are small-ish and portable, "fashionable" and <$200. Got anything to sell?
Can't let you have all the fun Steve Waitasec, how did I get lulled into soundscience?!? Assuming that the line drivers from the balanced outputs are basically referencing around "ground" without actually using it... it might somewhat better to try making a single ended adapter by dropping the negative legs and pulling over ground from somewhere else. Fun fact: a lot of balanced prosumer gear at the entry level doesn't even have symmetric output. The cold pin is often...