Electro-Voice EV-1244X
A modest add-on amplifier built around a decoder chip, with a $149.95 sticker that put four channels within reach of a stereo owner who already had a receiver.
Overview
The EV-1244X was not a receiver and never pretended to be one. Electro-Voice's own service documentation describes it plainly: a unit "designed primarily to add two back channels to an existing stereo system to provide easy expansion into 4-channel operation." That explains the box. It has a 3-3/8-inch-tall chassis, front/back speaker switching, a pair of 18-watt channels, and a STEREO-4 integrated circuit decoder inside. If a listener already owned a good stereo, the 1244X was the cheap way to bolt on a second amplifier pair and a decoder without throwing out the system they liked.
The power numbers are honest but modest. The manual rates continuous sine wave output at 18 watts per channel into 8 ohms, with an IHF music-power figure of 50 watts into 8 ohms and 65 watts into 4. That is not a powerhouse. It is an expansion amp, and the manual treats it as one. Frequency response is quoted at ±1.5 dB from 20 to 20,000 Hz at rated output, and ±1.5 dB from 20 to 30,000 Hz at one watt. Harmonic distortion is specified under 1.0% at rated output. Those are respectable figures for the price.
The decoder is the reason the unit exists. Per the service manual, the E-V STEREO-4 integrated circuit recovers four discrete channels from records and FM stereo broadcasts encoded with four-channel material, using conventional stereo phono cartridges and standard FM tuners. EV was candid about the other half of the story. On ordinary two-channel program, the decoder "creates a remarkable enhancement," which the manual openly admits "is not 'real' four-channel" but ranges "from pleasing to astounding, depending upon the information contained in the stereo signal." The decoder can also be switched out entirely. The Decode On/Off control and the Tape/Source switch let the 1244X run as a plain stereo amplifier when four-channel isn't wanted.
Electro-Voice positioned the 1244X alongside a standalone EVX-4 decoder, and the company's own advertising in HiFi/Stereo (May 1972, p.110) gave the pitch and the price together: the EVX-4 at $59.50 suggested resale, the E-V 1244X decoder/stereo amplifier at $149.95. That advertising also asked whether the EVX-4 could handle records encoded for Columbia SQ, Sansui, Dyna, and "all the rest," and answered with a single word: "Yes." Take that as marketing, not a lab verdict. EV's own copy in HiFi/Stereo (July 1972, p.114) conceded that in most cases listeners would hear "little or no difference" between decoders on demonstration records. It argued instead that some records might even sound better through the EV decoding because it was "basic" rather than over-engineered.
The connectivity is where the 1244X earns its keep as a system piece. Inputs cover magnetic phono, tuner, aux, and tape at high level, with phono sensitivity of 3 mV and the high-level inputs at 150 mV. There is a tape monitor with a Tape Mon 2/Normal switch, a Source/Tape mute, a speaker on/off, a loudness contour, and a front/back amp selector. The selector lets the owner decide whether the 1244X drives the rear pair or the front. Line outputs to other amplifiers are provided, so the unit can feed a bigger power amp if 18 watts per channel isn't enough. Speaker outputs accept 4-16 ohms per channel. A switched auxiliary AC outlet is on the back, and the whole thing runs on 110-120 volts, 50-60 Hz.
The control set is rotary and conventional: volume with a power switch, balance with a pull/mono switch, a phono/tuner/aux selector, and bass and treble each rated +10 dB / -12 dB at 50 Hz and 10 kHz respectively. Channel separation is specified at 40 dB minimum at 1,000 Hz. Hum and noise is better than 70 dB on the high-level inputs and better than 60 dB below rated output on the magnetic phono input.
Two details in the service literature matter to anyone who works on one. First, the manual notes that "due to the confidential E-V proprietary process," information on integrated circuit U1, the decoder chip, is not supplied. DC voltages and output RMS signal relationships are given so a technician can still diagnose around it. That means a failed decoder IC is the hardest thing to service on the unit. Second, the chassis parts list shows a metal screen cover, a front panel assembly, rubber feet, and standard slo-blo fusing (a 1½-amp output fuse and a 1-amp pigtail fuse), so the mechanicals are straightforward. The service manual itself was punched for a three-ring binder, with EV inviting technicians to add production changes and service tips as they arrived.
Collectors today treat the 1244X as a period curiosity more than a daily driver. It is a second amplifier, not a standalone system, and its 18-watt channels suit it to rear-channel duty or a small second zone rather than a main rig. The decoder is the historical draw. It was sold at a price that made matrix decoding an add-on rather than a new system. The service manual is complete, the parts lists are clear, and the description of what the decoder does and doesn't do is plain-spoken.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.