TEAC A-7300RX
A half-track open-reel deck that carried dbx Type I onboard — and weighed enough to make you plan the shelf before you planned the tape.
Overview
The transport alone nets 28 kg, and the amplifier section adds another 13 kg — so when a collector hauls an A-7300RX home, they are moving just over 41 kg of reel-to-reel hardware across two chassis. TEAC's own service documentation describes the A-7300RX as a high-quality stereo tape deck representing a new generation in design and construction, and it is candid that the basic design is highly similar to the earlier A-7300. What separates the RX is the built-in dbx circuitry: this deck includes the dbx Type I noise reduction system, and TEAC's manual credits it with superior live recording capability. Alongside dbx come an MPX filter, a CUE system, pitch control, and an edit function.
The head complement is a three-head arrangement — erase, record, and playback — running a half-track, two-channel stereo layout that also handles mono. Tape speed is switchable between 15 ips (38 cm/sec) and 7-1/2 ips (19 cm/sec), with ±0.5% speed tolerance and NAB equalization at both speeds. Reels up to 10-1/2 inches are accommodated, alongside 7-inch spools. The drive is a hybrid: one direct-drive DC servo capstan motor paired with two eddy-current induction reel motors. TEAC's service notes call the AC reel motors and DC direct-drive capstan highly reliable and state the machine should require a minimum of mechanical maintenance or adjustment — factory-set, with readjustment needed only after long service or component replacement.
The numbers back up the dbx pitch. Signal-to-noise is specified at 60 dB or higher with dbx engaged, dropping to 48 dB or higher without it — a 12 dB swing that tells you exactly what the noise reduction is buying. The manual's own record-mode S/N procedure lists 48 dB at both 15 ips and 7-1/2 ips. Total harmonic distortion is put at 0.8% with dbx at 1 kHz at normal operating level, and the distortion check procedure calls for 0.8% or less. Erase efficiency is 65 dB or more at 1 kHz, crosstalk rejection 35 dB or more adjacent-track at 125 Hz, and stereo channel separation 45 dB or more channel-to-channel at 1 kHz. Wow and flutter is quoted at 0.05% WRMS playback at 15 ips and 0.06% WRMS at 7-1/2 ips; overall figures run 0.12% RMS and 0.15% RMS respectively. Bias frequency sits at 100 kHz from a push-pull oscillator.
Inputs and outputs are studio-flavored rather than consumer-friendly. Line input is specified at -8 dB (308 mV) into 50k ohms with a minimum of -18 dB (97 mV); the mic input is a sensitive -60 dB (0.774 mV) into 30k ohms, with a -70 dB minimum. Source/tape output is specified at -8 dB (308 mV) into 10k ohms with a -2 dB (615 mV) maximum, the encoder output is specified at 8 dB (308 mV) into 50k ohms, and headphones run -24 dB (49 mV) into 8 ohms. Pitch control spans 3,000 Hz ±5% or more, and the manual's counter accuracy figure is ±1.5% at 15 ips play mode. Fast-forward and rewind of an 1,800-foot tape takes 150 seconds. Power draw is 83W from 100/117/220/240 VAC at 50/60 Hz.
Physically, the deck splits into two boxes: the transport measures 470 x 455 x 300 mm, the amplifier 470 x 205 x 310 mm. The service manual is dated effective October 1976, which is the firmest date the documentation pins down. The included accessories list is the sort of thing that separates a complete example from a bare one — two input-output connection cords, a low stray capacity cord, AC power cords (general export and Australia variants), 12P plug and socket cords, a TZ-275 cleaning stick, splicing tape, a silicone cloth, an M3 and M4 hex wrench kit, two TZ-612 reel adapter clamps, a cord case, 1A and 2A fuses, an owner's manual, an open reel supplement, and the RE-1002 10-inch empty reel, which the manual notes is an optional accessory ordered by model code rather than a special TEAC parts number.
Period advertising in the British press leaned hard on the dbx angle. A recurring listing for the Music Laboratory in Finchley described a "Teac master recorder with DBX" and a 100 dB s/n claim — a marketing figure well above the service manual's 60 dB with dbx, and a useful reminder that dealer copy and bench documentation rarely agree. Studio-Sound (June 1977, p.34) carried the same Music Laboratory advert, and the identical claim reappears in the October 1977 (p.18), November 1977 (p.16), and December 1977 (p.48) issues. Treat the 100 dB as sales copy, not a measured specification.
Collectors should note what the documentation does and does not settle. The service manual is explicit that the dbx encoder and decoder adjustments are critical and should only be performed by skilled technicians — so a unit with drifted dbx calibration is a bench job, not a DIY afternoon. The manual's mechanical section also prescribes a complete cleaning, demagnetization, and lubrication before any performance checks, which is the maintenance baseline for a machine of this age. Beyond the October 1976 service manual date, production years, original pricing, and current market values are not documented here; anyone buying should verify completeness of the accessory kit and the condition of the two-chassis interconnect before committing.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.