he does nice work... I've heard a comparison of his modded one with a u87, they're very different (just for the only comparison example I have heard with the modded mic). the blue spark modded does sound a little different from the stock one, and it should definitely have more proximity effect with the larger capsule.
The thing is, I really like the stock blue spark. I like smaller diaphrams sometimes for vocals, and the stock capsule and circuit are flattering to the four different singers I've tried through it so far (three were women though...).
So maybe it's more like an alternate flavor to get his mod. the really exciting news to me is that the mic CAN be modded at all. that opens up possibilities for a ton of very sexy looking bottle-type microphones to enter the DIY forums.
I want a spark with modified tone circuits - a switch to add air (12kHz resonant peak or something like that), a switch to add presenct (a 5k or 6k Hz 3db or so increase, maybe a shelf between 3k and 7k or something like that...?).... and why not. it's cheap, its sexy, it sounds really good stock, and based on what Joly's doing, it's moddable
