Music reference/ audio research / vpi

I think I remember Roger saying at an in-store seminar at Brooks Berdan’s shop in the early 1990’s that, though people believe tube brands all have their own distinctive, unique sound characteristics (Telefunken, Amperex, Mullard, etc.), the "sound" of a tube is actually the consequence of it’s electronic performance, nothing more. Two tubes from different makers that measure basically the same will sound basically the same. In other words, there is no mystery involved in what makes a tube provide a certain quality of sound. Yes, different brands were build to somewhat different specs and with somewhat different materials, but it is their measurable behavior that is responsible for their sound quality. Tim de Paravicini (EAR-Yoshino) told me the British tube companies would trade tubes with each other when they ran low of a given model, putting their own brand name on the other maker’s tubes and selling them as their own. Tim said he favours old Mullards because they were the best made tubes.

I imagine there are plenty of Audiogoners who disagree. I know this sounds just like Julian Hirsch and Peter Aczel (after his epiphany) on the sound of amplifiers, but there is a difference. Roger is not a meters-only kind of old-school EE designer, he uses his very good ears to design very good sounding amps (and now direct-drive ESL speakers---the output of an amp’s tubes---no output transformer---are connected to the ESL stators---no input transformer). He also now makes low-wattage single-ended amps, as well as push-pull.