Teac AL-700 (1976–1979)

Eighteen kilograms of diecast aluminum built to make a cassette sound like an open-reel, and the rarest Elcaset deck that ever shipped.

Overview

Eighteen kilograms. The AL-700 is a bookshelf Elcaset deck that weighs as much as a small open-reel machine, and every kilo of it is there for one reason. TEAC wanted to erase the line between cassette and reel-to-reel. The company's own literature claimed the AL-700 achieved "sound quality that matches the open-reel," and it backed the claim with a drive system borrowed conceptually from data recorders. That is instrumentation-grade engineering applied to a consumer tape format.

The format was Sony's gamble. Elcaset used a shell substantially larger than a Compact Cassette and quarter-inch tape running at 9.5 cm/s, and the AL-700 was TEAC's entry into it. The track format was four-track, two-channel stereo, with three heads (erase, record and play) and three motors: an FG servo DC capstan motor flanked by two coreless DC reel motors. The transport was a fully diecast aluminum closed-loop dual-capstan design. Modern Recording (May 1977, p.27) reported the unit as a three-head, three-motor machine with that diecast, double-capstan arrangement, and quoted weighted wow and flutter of 0.05%. TEAC's later published figure was tighter, 0.04% WRMS. Either number is remarkable for a cassette-adjacent format.

Frequency response ran to 25 Hz–22 kHz on Type II tape, and the deck accepted Type I, Type II, and Type III formulations with automatic bias and equalizer switching. Signal-to-noise figures vary by source: TEAC's published spec of 62 dB (NR out, 3% THD level, weighted) is the number to trust, though one contemporary account put playback S/N at 50 dB without Dolby and 53 dB with it engaged. The Dolby B circuit was claimed to buy 5 dB of noise reduction at 1 kHz and 10 dB at 5 kHz and above. THD was quoted at 0.8% on Type II.

Around 10,000 units were reportedly made, and the AL-700 is the rarest Elcaset machine actually produced. Original retail was $1,100 in the US and ¥198,000 in Japan around late 1976, which put it squarely in serious open-reel territory. By 1983, factory-sealed examples were being closed out at $349.

Key Features

Closed-Loop Dual Capstan with Magne-Float and Twin-Belt Drive

TEAC hung four specific technologies on the transport: a twin-belt closed-loop dual capstan, a semi-fixed head with high mounting accuracy, a self-aligning pinch roller, and a magne-float capstan. The logic is the same one that makes open-reel decks stable. The tape is controlled at both ends of the head block rather than dragged past it by a single capstan, and the diecast aluminum chassis keeps the whole geometry from drifting. The magne-float capstan is the detail that separates this from a rebadge. The drive is TEAC's own, not a Sony EL-7 or Technics design dressed up in a new box.

Three-Head, High-Hardness Permalloy Head Assembly

Separate erase, record and playback heads mean you can monitor off tape while recording. The playback head is a high-hardness permalloy type chosen for wear resistance. The semi-fixed mounting helps service as much as performance, since head alignment holds, and the plug-in board construction makes the deck notably easier to work on than the Sony Elcasets it competed against.

Dolby B with Copy Switch and dbx Provision

Dolby B was built in, and TEAC included a Dolby Copy Switch so owners could duplicate Dolby-encoded tapes without decoding and re-encoding. For buyers who wanted more, the separately sold RX-10 dbx unit could be connected. The wired RC-90 remote was also available separately.

Photoelectric Auto-Stop, Timer, and Memory Functions

The end-stop is photoelectric rather than mechanical, which shows where the money went. There's a timer mechanism, memory auto-stop and auto-play, and a one-touch Rec Mute for signalless recording. That last one is handy when you're laying down a tape and want clean gaps without stopping the transport.

Two Distinct Production Runs

Collectors note two versions. The earlier run carries a silkscreened model number, with serials beginning with #2. The later run wears a large three-part badge with an "ESOTERIC SERIES" tag on the lower tier, additional scripting above the door, and two prominent bolts, with serials starting #3. The earlier version is by far the more common, and Japan only saw that one. Both runs were exported.

Historical Context

The AL-700 arrived when TEAC's own trade catalog was describing Elcaset as "the most current topic, as a new standard for recording systems." That optimism didn't hold. The format was technically superior to the Compact Cassette of the day and died anyway, and the AL-700 went with it. It was rushed to market after lengthy engineering on more ambitious pre-production samples, then discontinued almost as quickly. TEAC reportedly allowed itself to sell, or more probably discount, a dismal number of units between 1978 and 1979. Sources place introduction at 1976 with discontinuation in 1979. Modern Recording (May 1977, p.27) had the deck scheduled for spring 1977 delivery, which fits a machine that was announced and then trickled out.

Collectibility & Value

Many consider the AL-700 the best Elcaset machine ever manufactured, and it's sought after for its precision and reproduction quality. That reputation has a price attached: a 2026 German listing asked €2,500 for an Esoteric Series example. Working units surface occasionally. One Russian listing described a restored US-market example with a transformer included and forty Elcaset tapes bundled in, and owners report new-in-box finds and fully recapped, re-aligned units still in service.

Serviceability is the saving grace. A 91-page English service manual exists, with block diagram, PCB layouts, schematics and parts list, and replacement belts are still being made. The plug-in board construction and metal case make restoration a realistic proposition. Buyers should confirm which production run they're looking at and check that the Elcaset shell itself (the media, not the deck) is included or available, because the tapes are the harder half of the equation now.