Sony TC-K71 Stereo Cassette Deck Manual (2024)

An examplary performer, in its time. A true hifi deck.

*****

In my DX hobby mostly, the TC-K71 rolled tapes for probably some 20 thousand hours or more, up until the deck's pinch rollers most likely gone worn, and the deck started having problems with tape guidance, on Basf and Maxell tapes.

Just yesterday, dug the deck out from my warehouse, after more than 20 years of ignoring. Belts dead, no surprise. Anyways, I cannot recall any other of my cassette decks having served for equal hours - with constantly winding tape back and forth, constantly starting recording, starting playback over again. Serves a cassette deck for recording and playing back albums, is no heavy duty. Yet has the mechanism to switch from mode to another, hundreds of times a day. For years, tens of thousands times. Talking about long lasting reliability. I have experienced some, say Aiwa and Technics decks, plastic parts breaking apart when rapidly switching between rec/play and wind modes.

*****

Reckon, I'll try obtain new pinch rollers and belts. TC-K71, dual capstan, very robust build with no disintegrating plastic parts. Of the premium class in cassette decks, in the days them best cassette decks were built to compete with the audio quality of reel-to-reel decks. TC-K71 tape counter is with memory feature, analog only though, and the level indicator only offers 1,5 dB resolution around level 0 dB. Loud mechanism, yet silent runner.

A nice feature is the level indicator peak hold, on them Sony top models early '80s:
one may choose either the automatic peak hold with its roughly half-a-second hold, or the manual peak hold while the highest peak keeping steadily lit until the peak hold got reset. I cannot instantly recall this kind of peak-hold feature in any other brand of my cassette decks, I owned from some 25 brands starting in 1972. While TC-K71 had no calibration circuit its big brother TC-K81 had, the TC-K71 manual BIAS calibration also only worked for Type I tapes.

*****

In 1980 [or was it 1981?], I bought the TC-K81 for my primary deck, and TC-K71 for my secondary deck. Back then, it was my two Sony TC-206SD decks, I updated.

In Finland, back then, the TC-K71 was more than USD 100 cheaper than TC-K81, yet the only difference with these two top-of-the-range Sony models was the calibration circuit on TC-K81. As for performance and build, TC-K71 was just equal. Back then, I did not find Pioneer top models meeting my preference, I had found Marantz decks unreliable, and so on. To Nakamichi, then. For the price of equally performing one Nakamichi deck, I was able to buy two of Sony top models, while saving some money for Sony premium tapes.

*****

Sony TC-K71. A serious HiFi deck? To performance, a true performer. To me, proved highly reliable. Still, the level indicator resolution could be better. Comes it to BIAS adjust only working on ferro tapes, BIAS calibration in the year 1980 was a novelty, rare on any deck. Considering the price tag back then, the audio quality, and the durability TC-K71 mine, I honestly can not rate below 4,5 // 5.

In the user manuals I got when buying my Sony decks TC-K81 and TC-K71, 40 years ago, Sony declares these models on
tape types III and IV produce 20-20000 Hz [30-18000 Hz +3 dB//DIN],
on type II 20-19000 Hz [30-17000 Hz +3 dB//DIN],
and on ferro tape Sony BHF 20-17000 Hz [30-15000 Hz DIN]. W&F claimed is 0,04 & WRMS.

Rather interesting is this spec in the manual given for type IV:
30-13000 Hz [+3dB, OVU]. The user manuals provided by Sony, as to frequency response, are somewhat interpretable reading. Even so, no tricks -20 dB, in the manuals specs.

Ilkka Suni,
Finland
KP41GD