Oh, one I forgot to mention that was first-rate is the $135 Pot-in-a-Box from Music Reference. On the down side, it is built with a cheap plastic box (though a metal box version is available for 3x the price), on the plus side, the plastic box is non-ferrous, and it has an extremely well made Noble attenuator made many years ago, that isn't made anymore because of the high cost of manufacturing. When you don't need buffering, hard to beat, except for the $450 Lightspeed Attenuator.