better preamps short-out unused inputs, provide SE and BAL inputs and outputs, use much-higher quality connectors, detachable power cords, resonant-free cabinets, longer lasting and quieter switching devices... another thing is the box needs to be stable and solid enought or it gets thrown all over the place by the sheer weight of the cables attached to it. otoh, you can buy a superb "used" preamp that used to be class "A" for 30 cents on the dollar. i set a limit on what i will spend on a preamp, and it's pretty high. but i will never buy a boulder or "whatever" for over $30k. not ever. and i respect boulder and fm acoustics, goldmund, kondo, etc. dynaudio even tried to market a $100,000 preamp awhile back. and what the heck was THAT suppose to sound like? but IMHO music sources aren't that good that i feel i need to worry about a $60K preamp. geez, man, just buy a steinway and get a piano teacher...