One of the biggest issues to consider when buying a headphone amp is how much coloration it has (how much the amp adds to the original music). All amps sound different, generally that difference is called coloration, and some amps have a lot more than others. This is an issue for the end user when deciding what to buy. Do you buy an amp that has a flat response or one that has some kind of sound altering circuit adding coloration to your music?
The HA543 addresses and completely solves this paradox. It features the best of both worlds. The HA543 is as flat as flat can be unaltering the original program material keeping it as true as possible. No coloration, no gimmicks nothing just absolute pure reproduction of the original material, and it sounds absolutely amazing with a good pair of headphones. Then, when using the HA543's Enhance switch, coloration circuits are added changing the overall sound characteristics.
The end result is an amp that makes the vocals sound more dominant, cymbals much more open and sharpens up the lower frequencies to give the bass very tight detail. It is not an EQ there's a lot more going on than just a simple EQ. It makes the HA543 two headphone amps in one. Want it purist flat? Its got that. Want a headphone amp that has some sound enhancing coloration? No problem.