Got the Stax 407 demo off Headamp, and I'm completely blown away. No doubt, technicallu the best headphone I've heard outside of the LCD2, and I only prefer the LCD2 due to it's warm colorization. The 407 is beautifully transparent, and extremely clean sounding without sounding sterile.
I've heard that the 507 is kind of bright. The 407 to me is actually quite neutral. The treble is well extended, but even with bright recordings, I don't get any fatigue. Basically the best treble I have ever heard on any headphone, period. I also heard the bass was supposed to be light. I appreciate my bass like any other person, yet, I don't find the bass lacking. It sounds neutrak. Quick and textured. Not slammy, but true to the recording.
Question, and only a question, what speaker amp could I pair with something like this? That SRM252S amp is quite small, and I don't know how well it could drive other Stax models. I think my next step is Stax, but I don't wanna pay an ungodly amount of money for an electrostatic amp if speaker taps would do me fine. If I could run it off my Marantz receiver's speaker taps, that'd be swell too...