CA-S1
(late 1978 - 1980)

Perpetuating the winning formula: the CA-S1 was part of small, transitional and Japan-only lineups, all more or less based on the CA-1010 / CA-1000III bestseller.

Just below the top of these "mini-series" (descending from the "R", very similar to the originals, to the "S", "X" and much lower "G", "V" and "Z") was the S1: slightly downsized (no Class A, smaller PTs, less heatsinking) but upgraded some: better componentry, high-Gm high-fT transistors, more elaborate circuits and tone controls, even better layouts and MC stages etc. and a novelty: the Output Impedance control, the function of which you can find outlined in the diagrams accessible below. A feature present in the B-4 power amp and several other integrated amps but substituted for LED meters in the export version (M-4)...

The tag for the CA-S1 was "The Extravagant Pre-Main Amplifier" - but it still was selling for less than the CA-2000 or CA-1000III ! Or: how to make just as good (or better) but for less money - the early 80s were approaching fast.