Got this as an upgrade from the built in headphone amp on my Apollo Twin X. For me the improvement is quite clear, however I have also tested with a producer friend of mine who struggled to hear a difference, with his own and my headphones. Possibly the difference is less noticeable due to its lower than average impedance for studio headphones on the MM-500s. For me, I can head a clear improvement in transient response across all frequencies, but a great improvement in clarity of the hi mids to high frequencies. I was instantly able to hear problem frequencies in these regions quicker when mixing.
In terms of the crossfeed functions, they’re not bad, it’s nice to have it as an option, especially since it’s analog and latency free. Compared to gHz CanOpener, I’d probably pick that, as it feels a bit more like a speaker setup. But in truth, I think it’s better to leave any crossfeed off altogether, as I hear most detail this way, especially with hard panned elements. I believe the MM-500s are staged in a way that is supposed to feel a bit more natural anyway.
Haven’t had the chance to compare to any other headphone amps, but honestly I’m happy. I’ve always felt the top end of my headphones was a little bit blurry, but now I feel like I can really dial it in.
In terms of negatives, it’s a bit big, takes up a fair bit of space on a desk. Wouldn’t want to transport it unless I have to. Crossfeed could be better but don’t think I’m going to use it too much anyway. VUs look great.
