Teac A-3300SX

The four-track quarter-inch deck that TEAC redesigned when tape itself changed - and kept everything that already worked.

Overview

The A-3300SX weighs forty-four pounds net and measures 440 by 440 by 210 millimeters. The transport uses three motors: a dual-speed hysteresis synchronous capstan motor and two eddy-current induction reel motors. That mass explains why these decks are still threading tape fifty years on. A synchronous capstan driven at line frequency holds speed in a way belt-driven consumer decks never managed. The reel motors handle 10-1/2" and 7" spools without strain. TEAC rated rewind and fast-forward at 140 seconds for 1,800 feet.

The A-3300SX is a quarter-inch, four-track, two-channel stereo (or mono) machine running 7-1/2 and 3-3/4 ips, with a three-head stack - erase, record, playback. TEAC's service documentation is explicit about the family. The A-3300SX and its half-track sibling, the A-3300SX-2T, share a chassis and manual, but they are different machines. The 2T runs 15 and 7-1/2 ips on half-track heads. The four-track A-3300SX runs the slower 7-1/2 and 3-3/4 ips pair. Buyers who want 15 ips want the 2T. Buyers who want to play back the bulk of consumer four-track tapes want this one.

The service manual's general description explains what the redesign bought. The A-3300S and A-2300S had been on the market for seven years and earned what TEAC calls an enviable reputation. Then more versatile tape formulations arrived, and they forced extensive modification and redesign so the decks could properly use them. The result was the SX generation, built for "complete flexibility in selection of recording tapes." It wasn't a new concept. It was a thorough revision of a proven one to keep pace with the tape being sold.

The numbers back up the revision. Wow and flutter is specified at 0.06% at 7-1/2 ips and 0.09% at 3-3/4 ips, NAB weighted. Frequency response is quoted overall at 30 Hz to 28 kHz at 7-1/2 ips, with a ±3 dB window of 40 Hz to 24 kHz, narrowing to 30 Hz–20 kHz overall at 3-3/4 ips (±3 dB: 40 Hz–16 kHz). Signal-to-noise is 58 dB overall, harmonic distortion 1% at 1 kHz at normal operating level, and stereo channel separation 50 dB at 1 kHz. Those are the figures of a serious home deck, not a toy — 28 kHz at the fast speed is genuinely wide, and the 0.06% flutter figure is the kind of number that keeps pitch stable on piano and sustained strings.

Around the back, inputs are two line at 100 mV into 100 kOhms and two mic at 0.25 mV (-72 dB) into 600 ohms or more. Outputs are two line at 0.3 V into 10 kOhms or more, plus a stereo headphone jack at 8 ohms. Bias comes from a push-pull oscillator at 100 kHz. Playback equalization follows NAB curves - 3180 µs and 50 µs at 7-1/2 ips, 3180 µs and 90 µs at 3-3/4 ips. The service manual's comparison table lists power consumption at 108 W for the four-track A-3300SX. A later correction sheet revises that upward depending on the market variant - 130 W for General Export and USA/Canada, 120 W for UK and Europe. It also revises net weight to 20 kg (44 lbs) for General Export but 21.5 kg (47.4 lbs) for USA/Canada, UK, and Europe. Trust the correction sheet over the original manual on those two points.

TEAC's period advertising leaned on the A-2300SX as the volume seller. Audio (October 1978, p.143) ran the company's copy claiming the A-2300SX was the best-selling open-reel machine ever, with over 300,000 sold. The A-3300SX sits above that machine in the lineup. It shares the transport architecture and electrical adjustment procedure but adds the 10-1/2" reel capability. The service manual states plainly that the electrical adjustment procedure for the A-3300SX and A-2300SX is identical, differing only in the tape speeds.

Maintenance is the usual vintage tape story, and TEAC's own manual is the place to start. The service literature instructs owners to thoroughly clean and demagnetize the entire tape path before any electrical work. It specifies TEAC TZ-261 cleaning equipment and the E-3 demagnetizer or equivalents. The trouble-shooting section covers both the A-3300SX and A-2300SX in a single guide. The manual also warns that the deck must be set to the proper voltage and frequency for the locality. These were sold in General Export (100/117/220/240 V AC, 50/60 Hz), USA/Canada (117 V AC, 60 Hz), and Europe (220 V AC, 50 Hz) variants, and a deck set for the wrong mains will not behave.

Supplied accessories from the factory included a 10-1/2" empty reel (RE-1002), reel adapters, a reel height adjusting sheet, input-output connection cords, an AC power cord, rubber feet, and splicing tape. Finding a complete example today is rarer than finding the deck itself, and the reel adapters in particular go missing.

The A-3300SX is not a 15 ips machine. That's the 2T's job. It is also not a quarter-track playback-only deck. The three-head stack allows post-record monitoring, which is why these still turn up in small studios and archives. It has a synchronous capstan, a documented adjustment procedure, and a parts lineage that stretches back through the A-3300S to the earlier A-3300.