I have both the old portable and 2 003's so obviously I like them. However I have often thought that they rolled off the treble too much. Still they are very listenable on a wide range of equipment. The portable is so nice to have on trips.
No question that the full-sized amps will outperform the portables. However if I have a full sized amp available I also have a Sigma/404, 007A or Sigma Pro as my preferred phones (and preferred in that order too.)
Right. I was mainly answering your question about the difference between the old and new earphones. Doesn't matter what amp you use so long as it's the same for both.
As for using a full-sized amp, not everyone has the luxury of owning some of the higher-end Stax. Stuff like the SR-Sigma aren't cheap anymore thanks to flippers on eBay, and at least compared to the Lambdas I think the earphones are actually pretty competitive. Smaller desktop amps from Stax or transformers can be found at fairly reasonable prices still.
More and more these days people are using IEMs for home listening, believe it or not.
Edited by MuppetFace - 2/21/13 at 9:00pm