Teac A-2340S
A quarter-track four-channel deck that asked buyers to thread 7-inch reels onto a machine built like a studio workhorse.
Overview
The A-2340S is heavier than its footprint suggests. The service documentation gives 21 kilograms net, in a chassis measuring 440 by 475 by 220 millimeters. That's a lot of iron and motor for a machine that tops out at 7-inch reels. The manual's specification section lays out the format plainly: quarter-track, four-channel stereophonic, with quarter-track two-channel stereo or quarter-track mono also possible. Three heads sit in the housing - erase, record, and playback - so tape monitoring and simul-sync work are on the table for anyone willing to learn the switching.
Two speeds, 7-1/2 and 3-3/4 ips, held to within half a percent by a dual-speed hysteresis synchronous capstan motor. Two eddy-current induction motors handle the reels. The transport numbers read like a deck built for repeatable work. Wow and flutter is specified at 0.18% RMS in playback at the higher speed and 0.20% at the lower. Overall figures creep up to 0.20% and 0.25% respectively once recording and playback are chained together. Fast forward and rewind are rated at 90 seconds for a 1,200-foot tape. That's not lightning, but it's fair for a consumer machine of this generation.
Signal-to-noise is where the era shows. The manual lists 47 dB or better at 7-1/2 ips and 45 dB or better at 3-3/4 ips. Ears used to digital numbers will wince, but that's the arithmetic of the period. Erase efficiency is 65 dB or more at 1 kHz, which keeps old tapes from bleeding through. Total harmonic distortion is stated at 1.5% or less at 1 kHz, and stereo channel separation is rated at 45 dB or more channel-to-channel at 1 kHz. Adjacent-track cross talk rejection is 35 dB or more at 125 Hz. Bias runs at 100 kHz from a push-pull oscillator, well out of the audio band.
The mic inputs accept a specified -60 dB (0.774 mV) signal into 10k ohms, with a minimum sensitivity of -70 dB (0.244 mV). Line inputs take -8 dB (308 mV) into 50k ohms, with a minimum of -18 dB (97 mV). The headphone output is -24 dB (49 mV) into 8 ohms. The line output is specified at -8 dB (308 mV) into 50k ohms, with a maximum of -2 dB (615 mV). 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 deck shipped with multi-voltage power options: 100, 117, 220, and 240 V AC at 50 or 60 Hz, drawing 110 W. The U.S. and Canadian version was fixed at 117 V, 60 Hz.
In the market, the A-2340S was Teac's attempt to put four-channel recording within reach of people who didn't own studio furniture. High Fidelity (February 1975, p.69) ran a Teac advertisement pitching the A-2340 as a machine for building a tape library tailored to the owner's tastes, priced at $739.50. HiFi-Stereo (July 1975, p.66) carried the same pitch at $779.50. By the time Studio-Sound (May 1976, p.9) got hold of the A-2340S, the framing had shifted to value. The ad copy called it the only budget recorder under £400 with 15 ips. That claim doesn't hold up, because the A-2340S manual specifies 7-1/2 and 3-3/4 ips, not 15. Either the ad copy is loose, or the A-2340S name was being used interchangeably with the A-3340 family in that era's marketing. Treat the "15 ips" line as advertising noise, not a spec.
The service manual is unusually thorough for a consumer deck. Pinch roller pressure is specified at 2.1 kg (4.6 lbs) with a tolerance of ±0.1 kg, and the adjustment procedure requires a spring scale and a careful reading of the instant the roller stops rotating. Take-up torque runs 380 to 400 g·cm; back tension 180 to 210 g·cm; brake torque 800 to 1,200 g·cm. The manual even names the cleaner, Teac TZ-261B, for brake drums and shoes. It warns against cleaning them unless absolutely necessary because brake torque changes with cleaning.
The A-2340S sits in a crowded Teac family. The brand catalog lists the A-2340R, the A-3340, the A-3340S, the A-3440, and the A-2340SX among its reel machines, and the naming is a minefield. Verify the exact model on the faceplate before assuming a spec sheet applies. The A-2340S manual's own note says "minor differences may be found between early and later machines" because of continuing changes during production. So even within a single model number, buyers may run into variations.
Today the A-2340S suits someone who wants four-channel quarter-track capability at 7-1/2 ips, values serviceability, and doesn't mind the weight. The 47 dB signal-to-noise figure is the ceiling, and the 7-inch reel limit means long-form recording requires swapping reels. The transport is overbuilt, the electronics are documented to a degree most consumer gear never was, and the three-head design gives it flexibility that two-head decks can't match.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.