Sony TC-640A

Sony TC-9400A

1 9 7 2 june 1972
1 9 7 4 1974

Smaller sibling of the TC-650 available in two chronological versions :

TC-640 sans FET, sans F&F heads and sans Uniphase but with the possibility of sound-on-sound and echo recording (september 1970, TC-9400 in Japan),
or TC-640A with FET-charged pb/rec amplifiers, F&F heads and Uniphase filters (june 1972, TC-9400A in Japan).

The original 1970 version was still sold in the USA as late as 1974 : an early example of Sony's habit of unleashing its old stocks there.

Also in true Sony fashion, the american TC-640 was advertised as TC-640B : normal since it came after the TC-640A on the US market but not normal since it was the original 1970 model and not the updated 1972 version which was named... 640A !
However, this old 640 rehashed for the US market inherited from the pause/lock function of the 640A so I guess it deserves its "B" name after all.

Both versions are nevertheless however mechanically identical :
three heads, three motors, 9,5 and 19cm/s speeds, Automatic Total Mechanism Shut-Off (TMS - it just stops all by itself at tape's end), high-frequency bias, stereo MIC/Line mixing, diecast tape guides, diecast head block frame, auto tape lifters, solenoid-operated near-feather-touch transport pads and one-button pause lock.
The capstan motor is an hysteresis synchronous ; the two reel drives are outer-rotor AC motors.

The original 1970 japanese model and the 1973 US model (ie. the TC-640B - following ?) have an an auto-stop function instead of the pause/lock button.

Programmed rec or play is possible with the optional DT-10 external timer/clock and cool looks with the beautiful but optional DP-10 smoked acrylic dustcover.

Empty reels could be the usual plasticky kind or the extra-rare R-7MA, an early variant of the oh so desirable R-7MB, the center of which was made of anodized diecast aluminium instead of plastic ; the first R-7MA had a different, somewhat triangular, lead-in area.

Even if not within a slanted enclosure like the TC-377 bestseller, the TC-640 could and still can be operated vertically as well as horizontally ; in the latter position, crucial adjustement points are all easily accessible from the bottom of the unit.

Sony TC-640A, image 1 Sony TC-640A, image 2 Sony TC-640A, image 3
Sony TC-640A specifications
Title Value
Frequency response : 20Hz...25Khz (19cm/s, SLH tape)
30Hz...18Khz (9,5cm/s, SLH tape)
Wow & flutter : 0,07% (19cm/s ?)
S/N ratio : 55dB
Rewind time : 90s (1200ft tape)
Record Bias : 120Khz
PC : 120W (60Hz models)
Dimensions : 36,9 x 39,5 x 24,35cm
Weight : 15kg.
List price : 76,800¥ (TC-9400, september 1970)
95,800¥ (TC-9400A, january 1974)
Sony TC-640A : 0 topic
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page online since : september 2009
page updated : may 2010
page type : LGT / KNB
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