I was around in the days of tubes as we Americans call them. One of my lab projects, in one of the schools I attended in the late 1940's, was to design and build a television set from scratch. It had 21 tubes and actually worked. Later, in the 1960's I bought an old vacuum tube Wurlitzer organ and replaced the guts with discrete solid state components. It is still working in one of my son's homes. Voicing in those days was done with operational and differential amps and active filters with everything analog. I haven't the faintest idea how some of the new digital stuff works. . .
[This message has been edited by Bob Hendershot (edited 04-16-2002).]