I'm beginning to realize how different DI boxes can be. Beyond simply transferring a 1/4" mono instrument pickup or device output signal into a usable balanced line-level signal, elements like EQ, transients and drive can be affected. The TD-100 is an affordable ($495) tube and sold state powered DI box, featuring variable input impedance/loading, polarity and ground-lift switches, a direct out multed from the input, variable output gain, and outputs for XLR mic level, 1/4" balanced, and even headphones! Most of the features should be self- explanatory, but the variable loading is certainly one not seen on many devices. This is invaluable in pulling the best sound out of different instruments - just turn the knob until it feels right (hint: use your ears). The output gain is obvious, but the tube stage can add a smooth crunch on top of the sound when pushed too hard - can be a good trick. The different outputs are a bonus too, and this is one of the few pro DI boxes with a headphone output, something that might be a plus for late night practicing. In use I found this DI to hold up with the best of my other boxes. On electric bass the low end was very deep and well-defined, the mids were present in a way that held up in a mix, and the tube added a bit of drive if wanted. On synths and drum machines, the tones that different levels of tube drive added were cool and made for some good timbre changes when needed. Even electric guitar sounded pretty good through the DI straight to tape - something I wouldn't usually count on with other boxes. There are things I like about the character of the various active DIs that I own, and the Summit TD-100 complemented them with another flavor that I found musical and desirable.