Editor's Note: Apart from the CAT, Shindo, and Placette, all the Class A preamplifiers offer balanced inputs and outputs. And unless noted, the preamplifiers listed do not have phono stages.
A
Audio Research Reference 6: $14,000
Replacing Audio Research's Reference 5 SE of 2011, the Reference 6 is a product in which everything—parts, circuitry, the whole megillah—has been revised, the upgrades including a heftier mains transformer, an improved volume-control circuit, and new custom-made capacitors. The audio circuits include three 6H30 dual-triode tubes…