TEAC AL-700 (1976) | Esoteric Series

The TEAC AL-700 Elcaset Deck was introduced in 1976 as TEAC's first—and only—Elcaset deck. Developed around the ambitious "Open reel sound on cassette" concept, it combined 6.3 mm-wide tape, high tape speed, and sophisticated open-reel-derived mechanics in a cassette format.

TEAC AL-700 Specifications

Model: TEAC AL-700 Elcaset Deck

Release: 1976

Track format: 4-track, 2-channel stereo

Head configuration: 3-head — erase, record, playback

Tape: Elcaset LC-60 / LC-90, Type I, Type II, Type III

Tape speed: 9.5 cm/s

Capstan motor: FG servo DC motor

Reel motors: Coreless DC motors ×2

Wow & flutter: 0.04% WRMS

Frequency response: 25 Hz–20 kHz ±3 dB, Type I; 25 Hz–22 kHz ±3 dB, Type II/III

Signal-to-noise ratio: 59 dB Type I; 62 dB Type II/III

Total distortion: 0.8% Type II

Fast rewind: Within 70 seconds with LC-60 tape

Inputs: Microphone and line, with independent level controls

Outputs: Line and headphone

Noise reduction: Dolby B, with external dbx capability

Power consumption: 37 W

Dimensions: 440 × 230 × 310 mm

Weight: 18 kg

Original sale price in Germany: 2.900 DM (dbx unit: 1.200 DM)

The Elcaset Concept

Elcaset was designed to bring open-reel performance to a cassette. The format was jointly developed by Sony, TEAC, and Technics and used 6.3 mm-wide tape—the same width used by open-reel machines—inside a much larger A-6-sized cassette. With a tape speed of 9.5 cm/s, the format offered considerably more tape area for recording than a conventional cassette. The result was an ambitious attempt to combine the convenience of a cassette with the sound quality associated with open-reel tape. A major difference was the outer tape guidance system. Instead of relying entirely on the precision of the cassette shell, the AL-700 pulled the tape out of the cassette and controlled it with the deck's own transport mechanism. This approach allowed TEAC to use sophisticated mechanisms such as a dual-capstan transport and three-head arrangement. TEAC's Open-Reel Technology in an Elcaset. Its three-motor drive system used an FG servo DC motor for the capstan and two coreless DC reel motors, directly reflecting TEAC's experience with three-motor open-reel machines. Twin-Belt Closed-Loop Dual Capstan. The twin-belt system was one of the AL-700's most distinctive mechanical features. Its closed-loop dual-capstan transport used two sets of capstans and pinch rollers to grip the tape and maintain controlled tension. The slight difference in capstan speed helped suppress tape movement and flutter caused by external disturbances. However, excessive speed differences could produce excessive tension, which was particularly undesirable with relatively thin Elcaset tape. TEAC therefore added a wide auxiliary belt directly to the outer flywheel. This belt acted almost like a mechanical servo, helping maintain soft and consistent tape tension while also reducing stress on the main drive belt and flywheel. High-Precision Fixed Head. TEAC also paid unusual attention to head mounting accuracy. The AL-700 used a fixed-head system derived from TEAC's in-vehicle data recorder technology. A precision die-cast structure and central locating pin determined the head's height, tangency, and tilt. Azimuth could then be adjusted with a single screw, allowing the head to pivot around the central reference point without changing its height. The result was a considerably more precise head-mounting system than the conventional three-point adjustment arrangement. Automatic Self-Aligning Pinch Roller. The pinch roller was another example of TEAC's data-recorder engineering. Several metal balls surrounding the roller shaft allowed considerably more movement than a conventional pinch roller. This gave the roller the ability to compensate for a tilted shaft or uneven rubber wear while maintaining even pressure against the capstan. Magnefloat Capstan. TEAC's Magnefloat system addressed unwanted capstan shaft movement. Magnets positioned near the flywheel and bearing used magnetic repulsion to keep the capstan shaft pressed against a defined point. Unlike a spring-loaded mechanical arrangement, the system produced very little mechanical noise and friction. It also avoided changes in clamping force caused by temperature variations and was designed for long-term durability. Three-Head Recording and Dolby Noise Reduction. The AL-700 used a true three-head configuration, with separate erase, record, and playback heads. The record and playback heads were made from high-hardness permalloy, while the erase head used ferrite. The deck supported Type I, Type II, and Type III Elcaset tapes, with automatic bias and equalization selection through detection holes in the cassette shell. Dolby noise reduction could also be selected automatically through the cassette's detection tab. The deck additionally incorporated an MPX filter to prevent problems caused by the 19 kHz FM stereo pilot signal during radio recording. For users wanting even greater noise reduction, TEAC provided a dedicated connection for the separately sold dbx RX-10 unit. Recording and Control Features. The AL-700 was far more sophisticated than a simple playback deck. Its microphone and line inputs had independent level controls, allowing microphone mixing during recording. A centrally positioned REC MUTE button made it possible to create silent sections while recording, while the large VU meters displayed average input level and independent peak indicators helped monitor momentary overloads. The transport was operated through soft-touch microswitches and logic circuitry. Additional functions included timer operation, memory auto-stop/auto-play, output volume control, mono/stereo switching linked to the microphone input, and a Dolby copy function. The Elcaset format itself provided automatic detection for tape type and Dolby selection, allowing the AL-700 to configure important recording and playback parameters without manual intervention.

External Accessories

The AL-700 could be expanded with dedicated accessories. TEAC offered the RX-10 dbx unit and RC-90 remote control as separately sold options. TEAC RX-10 dbx unit: ¥78,000 | TEAC RC-90 remote control: ¥10,500

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Technics SL-P1000 (1987) | The Class AA CD Player for Serious Hi-Fi

The Technics SL-P1000 was designed for listeners who wanted more than simply convenient digital playback. Introduced in 1987, this Japanese-made CD player combined Technics’ Class AA circuit technology, dual D/A conversion, sophisticated power-supply design, and extensive vibration control in a substantial 9.1 kg chassis.

Technics SL-P1000 Specifications

Manufacturer: Technics

Model: SL-P1000

Type: CD player

Production: 1987–1989

Made in Japan

Dimensions: 430 × 128 × 382 mm (W × H × D)

Weight: 9.1 kg

Original sale price in Germany: 2,500 DM

D/A conversion: Dual converter system with dedicated L/R converters

Digital outputs: Coaxial and optical

Digital filter: 96th-order high-resolution digital filter

Search: Two-speed search dial with three-frame precision

Remote control: Wireless 10-key remote with digital attenuator

Programming: 20-title program memory

Editing: Preset CD-to-tape editing function

Special functions: Programmable music scan

Drive system: Compact brushless direct-drive spindle

Pickup: Single-beam optical system with phase-difference tracking servo

Traverse mechanism: Linear-motor drive

Class AA is the heart of the SL-P1000. The design was inherited from the SL-P1200 and further developed for this model, with Class AA circuitry applied independently to the left and right channels in three important sections: the sample-and-hold circuit, buffer amplifier, and headphone amplifier. That makes a total of six Class AA circuit locations. The sample-and-hold stage receives particular attention. The voltage-controlled amplifier responsible for waveform transmission and the current-drive amplifier responsible for driving the holding capacitor and low-pass filter operate independently. The voltage amplifier therefore works under essentially unloaded conditions, helping improve the accuracy of the waveform produced during D/A conversion. Dual D/A Conversion. Dedicated converters for each channel are used for the left and right channels rather than sharing a single converter. This arrangement reduces L/R phase differences, while the current-mode operation of the converter output allows fast D/A conversion and helps improve high-frequency distortion and resolution. Super-Clean Digital Filtering. Digital filtering is another major part of the SL-P1000's architecture. Technics used a 96th-order digital filter together with an analog low-pass filter. The high calculation accuracy of this combination was intended to remove unwanted noise components generated during D/A conversion while preserving the musical signal. A Power Supply Designed for the Audio Circuit. Technics separated the digital and analog power supplies using two dedicated power transformers. The idea was straightforward: digital and servo circuits generate noise, so keeping their power supply separate from the audio circuitry reduces the possibility of that interference reaching the music signal. The audio transformer itself has separate secondary windings for the left channel, right channel, and headphone amplifier. A fast-recovery diode and high-capacity audio electrolytic capacitors are used in the rectification stage to reduce rectification noise and maintain a stable supply under demanding conditions. Active Servo Power Supply. The audio section receives its own low-noise Active Servo power supply. Technics combined a dedicated constant-voltage IC with a wide-band IC in a feedback circuit. According to the manufacturer, this arrangement reduced power-supply noise by more than 20 dB and provided exceptionally good voltage regulation. The intention was particularly important for low-frequency reproduction, where the SL-P1000 was designed to deliver a fast and powerful response. Vibration Control: Built Like a Precision Instrument. The SL-P1000 takes mechanical stability very seriously. Its three-layer weighted base combines the metal chassis with special damping rubber and Technics' TNRC (Technics Non-Resonance Compound). The different materials are designed to convert vibration energy into thermal energy, reducing unwanted resonance. Additional damping material is used on the cabinet top plate, while the optical deck is mounted using a floating structure. Floating Optical Deck. The optical mechanism is isolated from external vibration by a floating mounting arrangement combined with four large insulators. The design addresses vibration arriving through the installation surface as well as sound pressure and vibration transmitted from loudspeakers. Even the two internal power transformers are rubber-mounted to prevent their mechanical vibration from being transferred into the chassis. Precision Disc Reading and Fast Track Access. The optical pickup uses a single-beam system designed for high laser efficiency and an improved signal-to-noise ratio. The pickup assembly uses an aluminum die-cast base and a glass lens designed to remain stable against changes in temperature and humidity. A phase-difference tracking servo system further improves disc tracking and playability. The traverse mechanism is particularly sophisticated for its era. A linear motor moves the pickup, eliminating conventional gear-and-belt reduction mechanisms. Technics' microcomputer-controlled servo system could move the pickup between songs in approximately 0.9 seconds, while also improving quietness and durability. The Two-Speed Search Dial. One of the SL-P1000's most distinctive controls is its two-speed search dial. Turning the dial with the fingertips allows the listener to move precisely through the disc in either direction. Two search speeds are available: approximately one second per revolution in slow mode or approximately 30 seconds per revolution in fast mode. The finest access is possible in units of three frames, or 1/25 of a second, making the control unusually precise for locating a specific point in a recording. Digital Outputs and Remote Control. The SL-P1000 was designed to integrate with other digital equipment. It provides both coaxial and optical digital outputs, allowing the digital audio signal to be sent directly to an external D/A converter. The supplied wireless remote control provides a 10-key numeric keypad and access to the main playback functions, including search, repeat and time display.

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Aiwa CS-85X (1980) | CARRYIN COMPO Classic

The Aiwa CS-85X is one of those vintage Japanese audio products that immediately reveals how ambitious portable Hi-Fi had become around the beginning of the 1980s. Part of Aiwa’s CARRYIN COMPO series, it combines a sophisticated auto-reverse cassette mechanism, Metal tape capability, a powerful stereo amplifier, two-way speakers, radio, phono input, and even manual recording with large VU meters. This was far more than a portable cassette player. The CS-85X was designed as a complete stereo system that you could actually carry with you.

Aiwa’s Quick Reverse System. The most impressive feature of the CS-85X is undoubtedly its quick-reverse cassette mechanism. An infrared tape sensor detects the transition between the magnetic tape and its transparent leader. The mechanism then rotates the head through 180 degrees and reverses the direction of the tape. The entire operation takes approximately 0.4 seconds. That may not sound spectacular today, but for an early-1980s cassette machine it was a remarkable achievement. The extremely short transition was designed to ... Discover More