Yamaha K-700
Yamaha's answer to the auto-reverse azimuth problem - a rotating Sendust head that stays aligned in both directions.
Overview
Auto-reverse cassette decks had a dirty little secret in the early 1980s: side B almost never sounded as good as side A. Flip the tape, and the head geometry was off just enough to smear the highs and soften the image. Yamaha's own advertising for the K-700 went right at this, arguing that most manufacturers simply didn't bother with automatic azimuth adjustment on their reversing decks. The K-700's pitch was that it did, through a high-precision rotating head mechanism that permits precise, independent azimuth adjustment in both directions. Whether that claim holds up is another matter. Yamaha built the whole marketing campaign around it anyway.
The head is a pure Sendust type. Yamaha's copy notes it's the same head used in the company's top-of-the-line deck, which is aimed at buyers who assumed auto-reverse meant compromised playback. Sendust heads were prized for wear resistance and their ability to hold a stable gap. Putting one in a reversing mechanism is a harder engineering problem than putting one in a fixed-head deck. The rotating carriage has to return the head to the same azimuth on every flip, or the whole idea falls apart. Yamaha's solution was independent adjustment in each direction rather than a single shared setting.
The convenience features are what make the K-700 a recording deck and not just a playback machine. During recording, it counts down the remaining tape time, automatically fades out at the end of the tape, then fades back in after the tape reverses and continues recording. That is useful if you're taping a long set or a radio broadcast and don't want a hard cut at the flip. A separate fader button lets the user do fade-ins or fade-outs at any point during recording, independent of the end-of-tape behavior. The deck can also preprogram up to 15 selections to be recorded or played back in any order, which puts it in the company of decks costing considerably more.
The rest of the feature list reads like a checklist of early-Eighties cassette-deck ambitions: Intro Scan, Search, Blank Skip, Repeat, Auto Source Change, Auto Tape Selector, Dolby B and C noise reduction, a real-time digital counter, and an optional remote control unit. None of these are unique to the K-700 on their own. The combination is a lot of deck for what Yamaha pitched as a value proposition: auto-reverse with proper azimuth, programmable sequencing, end-of-tape fading, and Dolby C. The company's advertising closed with the line that the K-700 cost "much less than you'd expect to pay for this much deck," which is marketing speak, but it matches how the deck was positioned at launch.
Period coverage of the K-700 is thin, as it often is for mid-line decks. The launch campaign ran across multiple publications in late 1983, with the same core pitch appearing in Audio (September 1983, p.57), High Fidelity (October 1983, p.27), and HiFi-Stereo (September 1983, p.65), among others. Those placements are advertising, not independent testing. Yamaha's own copy asserts the azimuth claim, and the available documentation has no lab measurement of side-B azimuth stability. What the ads do establish is the feature set and the positioning.
By late 1984 the K-700 was showing up in dealer clearance listings at $365. That is a useful data point for what the deck actually sold for once the launch hype faded, and it puts the K-700 at the affordable end of Yamaha's cassette lineup rather than the flagship tier its head-sharing claim might imply. Anyone hunting one today should expect the usual caveats for a 1980s auto-reverse deck. The rotating head mechanism is the whole point and also the whole liability, and a unit that hasn't been serviced recently may not hold azimuth on side B at all. The Sendust head itself is durable. The carriage that moves it is the part that needs attention.
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