A sixteen-page Sony ES Component catalog from October 1986 - three ES families: integrated amplifiers TA-F555ESX/333ESX/222ESX, tuners ST-S555ESX/333ESX/222ESX, and the digital sound processor SDP-505ES. The ES concept is declared from the opening page: not merely Hi-Fi, but a «new reference» for the CD era - faithful reproduction of the diverse program sources of the new age.

The amplifier technical section focuses on two key developments. G-Chassis (Acoustically Tuned Gibraltar Chassis) is a die-cast aluminum monolithic enclosure that eliminates acoustic resonances from the chassis. S.T.D. Circuit (Spontaneous Twin Drive Circuit) employs two parallel output stages operating in Class A at low levels, extending the dynamic range to meet the demands of CD sources. The “Simple & Straight” principle is taken literally: no excess switches or intermediate buffers in the signal path.

The tuner section is built around Wave Optimizer Technology - Sony’s proprietary approach to radio signal processing. Three components: WOIS (optimized IF stage), WODD (direct detector bypassing the conventional discriminator), and WODSD (digital stereo decoder). The Super Sound Tracing Circuit in the stereo decoder adaptively suppresses noise on weak signals. The flagship ST-S555ESX carries all three technologies plus SST; lesser models receive them in varying combinations.

The SDP-505ES is a digital sound processor new to the lineup: Presence Delay for recreating concert hall acoustics, and Dolby Surround for matrix decoding of surround from stereo recordings. The back cover shows Sony demonstrating a 3D slide of a tropical island through the processor - a hint at “digital presence.”