Teac A-4010 (circa 1966–1970)

Forty-eight pounds of three-motor transport, and the deck that taught a generation of home recordists what "semi-pro" could mean.

Overview

The first thing you notice is the weight: 48 pounds for the A-4010, against 37 for the A-4000 and 40 for the A-4010L. The A-4010 is a three-motor machine - a dual-speed hysteresis synchronous motor on the capstan, plus two torque motors for the reel turntables - and the chassis was built to hold that arrangement steady through long sessions. It is a four-head, four-track, two-channel deck: erase, record, forward playback, and reverse playback. Reel capacity tops out at 7 inches, so this is not a 10½-inch semi-pro machine. It is a home deck with a serious transport under it.

Speeds are 7½ and 3¾ ips. At the faster speed the factory rates wow and flutter at 0.12 percent, and 0.15 percent at 3¾. Those numbers were respectable for the class and part of the reason the deck earned a following. Frequency response at 7½ ips is quoted as 30 to 20,000 cps, with ±3 dB limits of 50 to 15,000 cps. At 3¾ ips it runs 40 to 12,000 cps, with ±3 dB limits of 50 to 7,500 cps. Signal-to-noise is 50 dB at 7½ ips, measured peak record level to unweighted. Channel-to-channel crosstalk is 50 dB at 1,000 cps, and 40 dB between adjacent tracks at 100 cps.

The four-head layout is what lets the deck play in reverse without flipping the reel. A sensing post reads the foil at the end of the tape and trips the automatic switch-over to reverse playback. Teac's own advertising billed this as an "electrified automatic reverse system." The control set is what Teac called its symmetrical control system, a bank of electrically controlled, feather-touch push buttons that the company promoted as unique to its decks. A tape tension control switch rounds out the transport controls. It exists to protect thin, long-playing tape from being stretched or snapped by the reel motors. On a deck this old, that switch is often the difference between a working machine and a parts unit.

Connections run through the RA-40, a separate outboard record/playback amplifier that the deck depends on. Microphone input on the RA-40 is 10,000 ohms at 0.25 mV minimum. Line input is 100,000 ohms at 0.14 V minimum. Output is quoted at 12 volts into a load of 100,000 ohms or more. That is a high-level, high-impedance output, and it will not simply plug into a laptop interface without attention. The A-4010 draws 110 VA from 100/117/200 VAC at 50 or 60 cps. The A-4000 and A-4010L variants draw 100 VA. Cabinet dimensions for the A-4010 are 17¼ × 17½ × 9½ inches, and the RA-40 adds a 17¼ × 5 5/16 × 9¼-inch box, 10 pounds on its own.

Teac's advertising in the late 1960s leaned hard on the transport. A spread that ran in High Fidelity (October 1968, p.115) described the three-motor arrangement - dual-speed hysteresis synchronous for the capstan, two eddy-current outer-rotor motors for the reels - and claimed the configuration yielded less wow and flutter and more "studio-quality sound." The same advertisement listed four solid-state amplifiers, independent line and mic input controls, and walnut-and-brushed-chrome styling. That is advertising copy, not a lab report. But the architecture it describes matches what the service literature documents, which is more than can be said for a lot of period hype.

There is no long-form independent lab test of the A-4010 on the record. The surviving period coverage is largely Teac's own advertising plus the manufacturer's spec panel, so a review that may not exist is a poor reason to pay a premium. The HiFi-Stereo (March 1968, p.32) spec listing repeats the same figures - four heads, 4-track 2-channel, 7-inch maximum reel, 0.12 percent wow and flutter at 7½ ips, 50 dB signal-to-noise, 50 dB channel crosstalk - so the numbers are at least consistent across Teac's own materials.

What to Check Before Buying

These decks are roughly six decades old, and the failure points are predictable. The tape tension control switch and the sensing-post reverse mechanism most often need attention, because both involve mechanical linkage that stiffens with old lubricant. The RA-40 outboard amplifier is a separate unit and frequently goes missing. A deck sold without one cannot record or play back until it gets a replacement, and those are not common. Heads on a four-head machine are four separate wear items. Forward and reverse playback heads wear at different rates depending on how the previous owner used the deck, so inspect both. The capstan motor is a hysteresis synchronous design and holds up well, but the reel torque motors and their eddy-current control circuits are the more likely source of speed instability.

Cosmetics on these units were walnut and brushed chrome per Teac's own advertising, and the chrome shows fingerprints and pitting readily. That is a cosmetic issue, not a functional one, but it affects price in a market where condition drives everything.