(october 1975 - 1977)
Mid-end cuties in all of the ESII design glory : behaved silver chunks with TAC-15 sideburns.
The TA-3650 was just below the TA-4650 V-FET bestseller and is NOT equipped with V-FETs. The structure is all-DC differential amplifier.
Two phono inputs, two tape loops, presence and loudness switches, two turnover frequencies for each bass/treble controls, low & high filters, separable pre/main sections and a multi-voltage selector for the non-US and non-JP versions. Bar the damping factor, the 3650 specifications are quite similar to those of the 1971 TA-1130...
The 3650's 2x 55W are enough to shake da foundations whether you stroll along Peter, Paul and Mary or reach for heaven and hell with Carl maria von Weber's Freischütz.
The ST-3950 had the ST-4950 and ST-5950SD above him and did see a fairly rare (and useless anyway) ST-3950SD version which catered a supplementary switch for the (potential) Dolby FM broadcasts.
MOS-FET charged RF section, 4-gang varicap, highly stable local oscillator, 4 Uniphase filters, illuminted dial pointer when a station is tuned in, fixed & variable outputs and switchable signal/multipath meter on top of the main center tuning meter.
Bar a few items, the specifications are better than those of an ST-5150 and somewhat closer to an ST-5130 - Darwin was at work here.
Neither of these are masterpieces of audio but are already high-fidelity nevertheless. Reliable and looking good, too. The public probably saw this quite clearly as both units sold extremely well worldwide.
This line of mid-end separates was replaced by the TA-F5 and ST-A5 in 1977.
These two images come from a beautiful Sony summer 1976 UK catalog which abounds in good to excellent images where the Sony unparalleled work on textures, colors and finish choices is actually visible - something alas very, very rare in most Sony catalogs.