Right now, I am in the process of recording all my favorite music on to a small, portable recorder. For this purpose, about a year ago, I bought new a pair of $50 sony noise-canceling headphones. Obviously they are not anywhere near TOTL. I got used to how they sounded and thought it was decent for what I spent. I always thought the sound was a tiny bit off, but I attributed that to the recorder not being a very expensive or HiFi piece of tech. THEN, the other day i decided to try running that into my regular system using the original HP-2 headphones. I was utterly blown away by how good it sounded compared to the sony cans. I figured there would be an audible difference, but no where near what i was experiencing. I tried one and then the other to see how drastic the change was. The sony headphones were louder, but had a high end that sounded like needles compared to the yammies. The Yamaha set, though, had far less bass. So, that got me thinking about getting a different pair of Yamaha ortho's to use on-the-go. I realized I would probably need a portable headphone amp, but think I found a good one in the FiiO A3. Then I thought about all of the different models, thinking if I was to buy a new pair, I would want them better than what I have. This brought me to the HP-1A that is referenced in the brochure along with the HP-2. But getting online...there seems to be little to no reference of an HP-1A, just an HP-1. Is there any difference, is one better than the other, or is it basically the same with one more character added? I would appreciate your input on what is the best one of the old Yamahas as well as if you know of a different, better portable headphone amp.