OK so throughout a bunch of threads there has been discussion of a variable impedance box. (and preamps like the TD 100 that have them built in) What i want to know is: Is there such a device or a way of making one that is a very high quality audio device that only does that. No preamp, or gain or color or tubes or anything. It seems like from the one time I tried a TD 100 that it would be a great thing to have. I use an Avalon U5 cause it sounds so damn good, but if most of that is the way it deals with impedance, then I'd love to have a much smaller unit to sit on top of the Focus. I read the Steve Rodby quote where he says he has it built into his gear, but who builds them?