Electro-Voice Model 366
Two different products wore this number, and only one of them makes sound.
Overview
The Model 366 name is a trap for collectors. Electro-Voice used it twice in the same era, and the two items have nothing to do with each other. The one that shows up most in period print is the Model 366 Boom Shock Mount, an accessory for the E-V 666 microphone. The other is the Pilot 366, a quadraphonic receiver that E-V was selling by 1974. Anyone typing "Electro-Voice Model 366" into a search bar needs to know which one they're chasing, because the paperwork and the auction listings blur the two constantly.
Start with the accessory, since it has the longer advertising trail. The 366 Boom Shock Mount was an optional extra for the Model 666 dynamic microphone. E-V's own advertising in Audio (May 1954, p.35) pitched it for boom and fish-pole work. The mount weighed only 6 oz. and used adjustable rubber-band shock absorbers to isolate the mic from handling noise. It attached to standard booms, and E-V listed it at $40, which was real money in 1954 when the microphone itself listed at $245. The mount turns up in the same ad copy as the Model 300 Stand Coupler and the Model 420 Desk Stand, so collectors hunting a complete 666 rig are usually hunting all four pieces.
The receiver is the more interesting object and the more confusing one. The Pilot 366 was a big 4-channel receiver - 7 inches tall, 18½ inches wide, 17½ inches deep, and 44 lbs. - sold with a walnut enclosure at $499.90. The front panel carried a pair of microphone inputs with a dual level control, so the user could mix mic or instrument sources against any other program material. That was aimed at the audiophile who wanted quadraphonic sound with a bit of recording facility folded in. The mic mixing was the receiver's calling card, though period testing found the mixing control's behavior less clean than the feature list implied.
On the tuner side, the Pilot 366's FM section was rated at 1.8 µV IHF sensitivity with 65 dB signal-to-noise, 0.4% mono and 0.8% stereo THD, and 36 dB stereo separation at 400 Hz. Selectivity came in at 65 dB, capture ratio 1.5 dB, with 90 dB IF rejection, 80 dB image rejection, and 90 dB spurious response rejection. The AM section was far more modest: 200 µV IHF sensitivity off the internal antenna, 35 dB selectivity, 45 dB signal-to-noise, 60 dB image and IF rejection, and a 7 kHz bandwidth. So it had a serious FM front end and an AM section that existed because the market expected one.
The amplifier section is where the Pilot 366's specs get interesting — and where the marketing and the measurements part ways. E-V rated it at 60 watts per channel in stereo mode and 30 watts per channel in 4-channel mode, continuous power at 1 kHz, with 0.5% rated THD and 0.5% rated IM. Power bandwidth was quoted as 10 Hz to 40 kHz, high-level frequency response 15 Hz to 25 kHz ±1 dB, damping factor 35 into 8 ohms. Input sensitivity ran 2.5/4.5 mV for Phono 1 and 2, 250 mV high level, 1 mV microphone, with tape output at 350 mV. The power requirements were 120 V at 50/60 Hz.
Period testing told a different story. It measured THD at 0.7% and IM distortion at 0.8% at rated output, slightly above the 0.5% claims. At lower levels distortion stayed near 0.5% and IM dropped to roughly 0.4%. The same review noted that the 10 Hz to 40 kHz power bandwidth figure was referenced to 30 watts per channel, and that actual rated-THD power came in slightly below 30 watts, so the bandwidth curve sat below the 0 dB reference in mid-band. The reviewer's point was that had Pilot rated the unit more conservatively, say 25 watts per channel, the power bandwidth would have extended beyond the quoted 10 Hz and 40 kHz limits. Driving the amplifier to 30 watts at 20 Hz pushed THD to about 2%, though at half power distortion stayed fairly flat across the spectrum. The bass boost control was flagged as "a bit extreme" and best used in moderation to avoid overloading the amp at low frequencies. The low-frequency filter rolled off at 12 dB per octave, while the high-cut filter behaved more like a treble cut at only 6 dB per octave. The loudness contour, measured 30 dB below maximum volume, emphasized treble as well as bass, with the treble boost kept moderate.
So the Pilot 366 is a feature-dense quad receiver whose measured performance was good but not quite what the spec sheet promised. Its most distinctive feature, the front-panel mic mixing, was also its most awkwardly implemented. Collectors who find one today are usually drawn to the mic inputs and the quad-era completeness.
The naming collision is the practical headache. Auction listings and parts listings for "E-V Model 366" can mean either the $40 boom mount or the $499.90 receiver. The accessory shows up far more often because E-V advertised it across multiple 1954 issues of Audio alongside the 666 microphone. Buyers should confirm dimensions and weight before committing. 6 oz. versus 44 lbs. is a decisive tell.
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