Sony's original audiophile, high-end and professional Tapecorder.
Its features and reliability were sufficient to make the TC-777 not only a sought-after recorder in the early 1960s but also a reliable workhorse still available for sale (and selling) in the early... 1980s !
Sony made its original reputation with tape recorders - a reputation and market-share that still is unmatched by anyone : professional video meant and still means Sony with 1" in the 60s and 70s, Betacam in the 80s, Digibeta and DV-Cam in the 90s and XD-Cam today. Plus professional audio for about 20 years with the PCM-3348 series.
There were many versions of the TC-777 made, most of which I haven't yet yet traced or found the differences and peculiarities of : TC-777, TC-777S, TC-777A, TC-777M, TC-777-2 and 2J, TC-777-4, 4J and S-4J... probably a few more I have yet to unearth in my 1960s french and japanese catalogs plus the Sony DIGIC corporate magazines and 1978 Sony "bible".
The most common seem to have been the original 777 (1961), the 777A (1963) and the 4J (1964).
The features are about the same as those found in later recorders : three motors, three heads, mic/line mixing, sound-on-sound, tape/source monitoring etc but four of the original features do stand out :
the four PCBs inside the 777 are "plug-in" type à la Sony TA-2000 or Kenwood Supreme 1 - that's four years before the 2000 and six years before the Supreme.
Also solenoid-operated transport controls !
Also XLR balanced inputs - in 1961 !
The Electro Bi-Lateral heads incorporate both 1/4 and 1/2 track stereo cores within each head so that each model can replay tapes recorded on the other : 4-t rec, 2-t play, 4-t play (S4) or 2t-erase, 2-t rec, 2/4-t play (S2).
The patented Sony Trac-Stan drive is centered around a capstan that has a traction tread surface above and below the tape contact area and a statically balanced tape tension stabilizer. 3" illuminated precision VU meters, automatic tape lifters and all-Sony transistors and diodes provide convenience and stability.
Shown here by way of a circa 1964/65 USA catalog with the optional RMA-719 rack mount adaptor (9,50$), SSA-777 powered loudspeakers (175$) and MX-777 stereo mixer ("less than 175,50$") ; the more common MX-600 mixer was also available.
Complete with carrying case and remote control, the TC-777-4J cost 695$ in 1965 - quite a sum for the amateur recordist !
The 777 name, btw, stuck on Sony for many of its all-time best : TC-K777, TC-K777ES, TC-K777ESII, TA-F777ES, CDP-X777ES, CDP-777ESA, CDP-777ESJ, SCD-777ES, TA-FA777ES...