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By LARRY MYERS 1976 - nicht mehr By THOM PRINGLE

HOW OFTEN HAVE you heard someone say "Use your head"? Well, if you are a hi-fi fan, that expression takes on an entirely different meaning. Because, you can "use your head" to enjoy high-fidelity sound without disturbing your family or the folks next door - or down the block if you really like your music loud.

Yes, headphones are an important hi-fi accessory. Even if you've invested hundreds of dollars in massive power amplifiers and exotic loudspeakers, you'll still find headphones useful.

Besides letting you listen to music without disturbing others, headphones have a number of other uses. For example, while recording you need to listen really closely to make sure you are getting the best possible performance from your tape machine.

Headphones are one way - and many would say the best way-of doing just that. Because the headphone transducers are but millimeters away from your ears, the sound isn't effected by room acoustics, extraneous noise or the speaker/listener relationship.

Headphones can be a trouble-shooting aid, too. If you are having problems with your equipment you can often isolate it to a particular component with 'phones. Suppose you find yourself with a lot of distortion or noise whenever you use your cassette deck.

Just plug the phones directly into the unit's jack. If the problem is with the deck you'll hear it. If not, you've at least eliminated one potential cause of the trouble.

Now that may not seem like a lot of help, but it will save you from hauling the wholesystem off to the repair shop. Headphones can help with other "bugs", too, but we don't have the space to go into all the details here. Suffice it to say they can help locate problems in your receiver's tuner, pre-amplifier and power-amplifier sections, and even in your speakers.
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There are two basic approaches to earpiece design. The closed headphone has large liquid or foam-filled ear cushions that encircle the ear to provide a tight seal for good audio coupling, and up to 40 dB of isolation from the sounds around you.

The open or non-isolating headphone has cushions that rest lightly on the ears and permit the listenerto hearconversation and extraneous sound. The open type is lighter in weight and is, for some, more comfortable for long periods of wear. The choice between the two designs is largely a personal one.
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Headphones are basically miniaturized loudspeakers consisting of elements that are usually dynamic or electrostatic, in construction. The term 'dynamic' covers a broad variety of transducer designs where an electromagnet causes a thin metal or metalized diaphragm to vibrate at audio frequencies.

Electrostatic elements create sound waves by varying an electrostatic field that surrounds a thin plastic film. Unlike the dynamic type, electrostatics require an external power supply, though there are a few 'self-energizing' models as well as permanently energized 'electret' types that dispense with the power supply. Electrostatic designs are invariably more costly than the dynamic type, and offer the broader-than-average frequency response that is characteristic of this type of transducer.

There are some other transducer approaches on the market now that are fairly radical departures from the types just mentioned. One manufacturer is using a pizoelectric transducer. It consists of a plastic film with a very thin layer of aluminum on both sides. When a voltage is applied to the aluminum the plastic expands and contracts, moving the surrounding air.
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Another approach uses the Heil Air-Motion transformer. This transducer uses a folded diaphragm that squeezes the air out as it moves. (Both the pizoelectric and the Heil approach are also used in some speakers.)

There are numerous two-way systems among the latest headphones, employing miniaturized woofers and tweeters, and at least one hybrid design with electrostatic tweeter and dynamic woofer.

Manufacturers of budget-priced dynamic headphones employ, as a rule, conventional designs and provide little information on their construction, while those producing premium-priced 'phones often provide elaborate diagrams and detailed specifications on their innovative designs.
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While most headphone specifications indicate frequency response, there is rarely an indication as to how much it varies from the ideal or 'flat' response (for example, ±3dB). So, while today's top quality stereophones cover the full audio spectrum of 20-20,000 Hz, the buyer will do well to compare the sound of several models and let his own ears judge the unit's performance.
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The miniature speakers in stereo headphones usually have a power handling capacity measured in fractions of a watt. Often it is stated in terms of RMS voltage. The headphone jack on stereo receivers delivers the correct voltage to drive the 'phones with little danger of overload, but if the user makes his own headphone connections, say at the output terminals of an amplifier, care must be taken not to damage the headphones with excessive power.
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Like loudspeakers, stereo headphones should be matched to the output impedance of the amplifier, usually 4-16 ohms. However, some preamplifiers and special components require headphones with 300, 600, or 10,000 ohm (10k ohm) ratings. Several manufacturers offer mid- and high-impedance versions of their headphones. Check the instruction manual of your equipment to determine what headphone impedance is recommended.
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Some models offer individual volume controls, built into each earpiece, so the sound level can be adjusted at a distance from the amplifier. There is a further trend toward building electronic circuitry into headphones, to control separation and ambiance, variable blending of left and right channels if desired, or to provide matrix circuitry for a pseudo-quadraphonic effect.
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The earpieces of 4-channel phones are slightly elongated and divided into front and rear sections, each containing individual speaker elements. Sometimes there are separate tweeters for front-rear separation and a single woofer for the less-directional bass frequencies. Quadraphonic phones usually feature a stereo/4-channel mode switch as well as volume and balance controls.
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Now virtually standard is the coiled cord, with hefty 3-conductor phone plug already attached (though some European makes employ DIN-type speaker plugs for headphone connections).

There are numerous accessories offered - control boxes, special amplifiers and adapters - to add to the convenience of using headphones. And there's room too for further innovation, such as the clothespin-like clip attached to the cord of one model, so the user can move about more freely without the cord tugging at the ears.

Although not available in the military market as yet, several European firms have shown special wireless headphones. A special transmitter sends infrared frequency signals through the air to sensors on the headphone. With this system you don't have to worry about wires at all!

While we are on the topic of conveniences, remember that unlike any other part of your hi-fi system, headphones are worn on your body. Now, that means you want them to fit comfortably, like you favorite shirt. It wouldn't be a bad idea to try on several different models before you buy.

After all, why spend your money on something you won't enjoy? That wouldn't be using your head.
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Dokorder
Dokorder HS-303D - Stereo dynamic headphone, impedance 8-16 or 20k ohms (switchable), frequency response 1 5-23k Hz. Maximum power input 0.5 watt. Individual volume control on each earpiece. Padded, foam-filled headstrap and ear cushions. Coiled 1 1 -ft. cord. Wt. 1 6 oz.

ESS
Ess Amt-Stereo Heil Air-Motion transformer headphones. Impedance 32 ohms, frequency response 20-50k Hz, distortion 0.3 per cent at 90 dB. No special power supply needed. Connects to amplifier outputs. Foam-filled ear cushions. Coiled 14-ft. cord. Wt. 14 oz.
Hear Muffs Hear Muffs HM 4000 - Stereo dynamic headphones. Impedance 4-16 ohms, frequency response 30-18k Hz. 4-in. dynamic drivers mounted in U-shaped pillow which fits around head. Various colors. Coiled 10-ft. cord. Wt. 21 oz.

JVC
JVC 5844 - 4-channel/stereo dynamic headphone. Impedance8 ohms,frequency response 20-20k Hz. Harmonic distortion 0.5 per cent. 4-channel/stereo switch. Padded headband and foam-filled ear cushions. With 61 2-ft. cord. Wt. 17 oz.

JVC 5944 - 4-channel/stereo dynamic headphone, impedance8 ohms, frequency response 20-20k Hz. Distortion at normal listening level 0.5 per cent. Maximum power input 0.1 watt. Built-in switch for 4-channel/stereo selection. Padded, foam-filled headstrap and ear cushions. With 6.5-ft. cord. Wt. 14 oz.

JVC HP-20-Stereo dynamic headphone. Impedance 8 ohms, frequency response 20-20k Hz, distortion 1.0 per cent. Maximum input 500 milliwatts per channel. Padded headband and ear cushions. 10-ft. cord. Wt. 151/2 oz.

JVC STH-10E - Stereo dynamic headphone. Impedance8 ohms, frequency response 20-20k Hz. Volume controls for left and right channels. Padded headband andfoam-filledearcushions. With 61/2-ft. cord. Wt. 14 oz.

Kenwood
Kenwood KH-32 - Stereo dynamic headphone. Frequency response 20-20k Hz. Open-air type.

Kenwood KH-52 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 20-20k Hz. Openair type. Padded headband and ear cushions. 10-ft. cord. Wt. 101/2 OZ.

Koss
Koss ESP-6A - Stereo self-energized electrostatic headphone. Impedance 4-16 ohms, frequency response 30-19k Hz (± 5 dB), distortion 0.2 per cent at 109 dB. Maximum input 10 volts rms. Padded headband and air-filled ear cushions. Microphone mount. Coiled 10-ft. cord. With control box. Wt. 27 oz.

Koss ESP-9-Stereo electrostatic headphone. Impedance 4-16 ohms, frequency response 10-19k Hz (±5 dB), distortion 0.13 per cent at 110dB. Maximum input power 12 watts. Maybe operated from external power supply (included) or in self-energizing mode. Padded headband and air-filled ear cushions. Microphone mount. With 6-ft. cord and power supply/control unit. Headphone wt. 19 oz., power unit, 3 lbs. 110/220 volts.

Koss HV-1 - Stereo dynamic headphone, impedance 3.2-600 ohms, frequency response 20-20k Hz. Distortion 0.5 per cent at 109 dB. Maximum input 5 volts RMS. Open back, hear-through earpiece design. Sponge-type ear cushions. Coiled 10-ft. cord. Wt. 9.5 oz.

Koss HV-1A - Stereo dynamic headphone. Impedance 4-600 ohms, frequency response 15-20k Hz, distortion 0.5 per cent at 109 dB. Maximum input 5 volts rms. Open air design. Sponge-type ear cushions. Coiled 10-ft. cord. Wt. 9 oz.

Koss HV-1LC - Stereo dynamic headphone. Impedance 4-600 ohms, frequency response 15-20k Hz, distortion 0.5 per cent at 109 dB. Maximum input 5 volts rms. Open air design. Volume controls on each earpiece. Sponge-type ear cushions. Coiled 10-ft. cord. Wt. 10 oz.

Koss HV-2 - Stereo dynamic headphone. Impedance 4-600 ohms, frequency response 20-20k Hz, distortion 0.5 per cent at 109 dB. Sponge-type ear cushions. Open air design. 6-ft. cord.

Koss K-2+2 - 4-channel/stereo dynamic headphone. Impedance4-600 ohms,frequency response 10-20k Hz, distortion 0.5 per cent at 110 dB. Maximum input 5 volts rms. Each earpiece contains two separate transducers. 4-channel/stereo switch. Padded headband and fluid-filled ear cushions. Two coiled 10-ft. cords. Wt. 26 oz.

Koss K-6 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 10-16k Hz, distortion 1.0 per cent at 95 dB. Padded headband and air-filled ear cushions. Coiled 10-ft. cord. Wt. 15 oz.

Koss K-6LC - Similar to Koss K-6 except has volume control on each earpiece.

Koss K-6LQC - 4-channel/stereo dynamic headphone. Impedance4-600 ohms, frequency response 20-17k Hz, harmonic distortion 0.5 per cent at 109 dB. Each earpiece contains two separate transducers. 4-channel/stereo switch. Individual volume controls on each earpiece. Padded headband andfoam-filled earcushions. Two coiled 10-ft. cords. Wt. 22 oz.

Koss KO-727B - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 10-18k Hz. Foam-filled ear cushions. Padded headband. Coiled 10-ft. cord. Wt. 19 oz.

Koss KO-747 - Stereo dynamic headphone. Impedance 4-600 ohms, frequency response 30-20k Hz, harmonic distortion 1.0 per cent at 110 dB. Volume controls on each earpiece. Padded headband and fluid-filled ear cushions. Coiled 10-ft. cord. Wt. 21 oz.

Koss KO-747Q - 4-channel/stereo dynamic headphone. Impedance4-600 ohms,frequency response 20-20k Hz, harmonic distortion 0.5 per cent at 110 dB. Two separate transducers in each earpiece. 4-channel/stereo switch. Individual volume controls on each earpiece. Padded headband and air-filled ear cushions. Two coiled 10-ft. cords. Wt. 22 oz.

Koss Phase/2 - Stereo dynamic headphone. Impedance 4-600 ohms, frequency response 10-20k Hz, distortion 1.0 per cent at 100 dB. Programmer has panoramic source control, ambience expander. Microphone mount. Padded headband and air-filled ear cushions. Coiled 10-ft. cord. Wt. 24 oz.

Koss Phase/2+2-4-channel/stereo dynamic headphone. Impedance 4-600 ohms,frequency response 20-20k Hz, distortion 1.0 per cent at 100 dB. Programmer provides 127 listening perspectives. Foam-type ear cushions. 312-ft. cord from headset to programmer, 3-ft. coiled cord from programmer to jack.

Koss Pro-4AA - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 10-20k Hz, harmonic distortion 0.5 per cent at 110 dB. Maximum input 2.5 volts rms. Padded headband and air-filled ear cushions. Microphone mount. Coiled 10-ft. cord. Wt. 19 oz.

Koss Pro-5LC - Stereo dynamic headphone. Impedance 4-600 ohms, frequency response 10-20k Hz, harmonic distortion 0.5 per cent at 110 dB. Individual volume, balance controls on each earpiece. Air-filled ear cushions. Coiled 10-ft. cord.

Koss Pro-5Q - 4-channel/stereo dynamic headphone. Impedance 4-600 ohms, frequency response 20-20k Hz, harmonic distortion 0.5
per cent at 110 dB. Air-filled ear cushions. Two coiled 10-ft. cords.

Koss Technica/VFR - Stereo dynamic headphone. Impedance 4-600 ohms, frequency response 10-22k Hz, distortion 0.4 per cent at 100 dB. Controls allow user to change frequency response contours. Air-filled ear cushions. Coiled 10-ft. cord.

Marantz
Marantz SD-5 - Stereo dynamic headphone. Impedance 8 ohms, frequency response 30-15k Hz, distortion 0.18 per cent at 100 dB. Sensitivity 15 volts rms. With coiled cord. Wt. 16 oz.

Panasonic
Panasonic EAH-22 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 20-20k Hz, maximum power input .4 watt. 212 in. drivers. Padded headband, ear cushions. Coiled 10-ft. cord. Wt. 14 oz.

Panasonic EAH-23 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 20-20k Hz, maximum power input .7 watt. 214 in. drivers. Padded headband, ear cushions. Volume control on each earpiece. Coiled 10-ft. cord. Wt. 17 oz.

Panasonic EAH-35 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 20-20k Hz, maximum power input .2 watt. 2 in. drivers. Foam-type ear cushions. Coiled 612-ft. cord. Wt. 121 4 oz.

Pioneer
Pioneer SE-Q404-4-channel/stereo dynamic headphone. Impedance 8 ohms, frequency response 20-20k Hz. Maximum power input .5 watt. 4-channel/stereo mode switch, separate volume controls on each earpiece. Two driver elements in each earpiece. Padded headband and ear cushions. With 9-ft. cord. Wt. Vk lbs.

Pioneer SE-205 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency range 20-20k Hz, maximum power input 0.5 watts. Foam-filled ear cushions and headband. 8-ft. cord. Wt. 16 oz.

Pioneer SE-305 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 20-20k Hz. Maximum power input 0.5 watt. Pedded head band and foam-filled ear cushions. Coiled 16-ft. cord. Wt. 15 oz.

Pioneer SE-505 - Stereo dynamic headphone. Impedance 4-16 ohms, frequency response 20-20k Hz, maximum power input 0.5 watts. Each earpiece is two-way system consisting of separate woofer and tweeter. Separate volume controls on each earpiece. Coiled 1 6-ft. cord. Wt. 24 oz.

Sansui
Sansui QH-44 - 4-channel/stereo dynamic headphone. Impedance 25 ohms, frequency response 20-20k Hz. Open-back hear-through earpiece design. Rear channel volume control, 4-channel/stereo selector switch. Foam-type ear pads. 8-ft. cord. Wt. 15oz.

Sansui SH-15 - Stereo dynamic head-
phone. Impedance 25 ohms, frequency response 20-20k Hz. Maximum power input 0.65 watt. Removable, washable foam type earpads. 10-ft. cord. Wt. 9 oz.

Sansui SS-10 - Stereo dynamic headphone, impedance 8 ohms, frequency response 20-20k Hz. Maximum power input 0.5 watt. Individual volume control on each earpriece. Padded headband and foam-filled ear cushions. Coiled 10-ft. cord. Wt. 22 oz.

Sansui SS-20 - Stereo dynamic headphone, impedance 8 ohms, frequency response 2O-20k Hz. Maximum power input 0.5 watt. Each earpiece has two-way system consisting of cone-type woofer and cone-type tweeter. Individual tone and volume controls on each earpiece. Padded headband and foam-filled ear cushions. Coiled 8-ft. cord. Wt. 27.4 oz.

Sansui SS-35 - Stereo dynamic headphone. Impedance 8 ohms, frequency response 20-20k Hz, distortion 0.15 per cent. Maximum power input .3 watt. Padded headband and detachable ear cushions. With 8-ft. cord. Wt. 16 oz.

Sansui SS-50 - Stereo dynamic headphone. Impedance 8 ohms, frequency response 20-20k Hz. Maximum power input
0.5 watt. Each earpiece is two-way system consisting of separate cone-type woofer and dome-type tweeter. Separate tone and volume controls on each earpiece. Padded headband and foam-filled ear cushions. Coiled 10-ft. cord and 7-ft. extension cord. Wt. 28 oz.

Sennheiser
Sennheiser HD-424 - Stereo dynamic headphone. Impedance 2k ohms, frequency response 16-20k Hz. Foam-type ear pads. 10-ft. cord. Wt. 6.5 oz.

Stax
Stax SR-3 - Stereo electrostatic headphone. Impedance 4-16 ohms, frequency response 30-25k Hz. Requires Stax SRD-6 adapter/ power supply. Adjustable headband, vinyl ear cushions. Wt. 15 oz. SRD-6 operates from 110/220 volts.

Stax SR-X -Stereo electrostatic headphone, impedance 4-16 ohms (with power supply), frequency response 30-30k Hz. Requires 200-volt polarizing potential. Designed for use with Stax SRD-7 adapter/power supply. Adjustable headband and vinyl ear cushions. Headphone wt. 13 oz. SRD-7 unit operates from 1 1 0-220 volts ac.

Sony
Sony DR-5A - Stereo dynamic headphone, impedance 8 ohms, frequency response 50-17k Hz. Maximum input power 0.1 watt. Foam-filled ear cushions. With 6-ft. cord. Wt. 15 oz.

Sony DR-7 - Stereo dynamic headphone, impedance 8 ohms, frequency response 50-17k Hz. Maximum power input 0.1 watt.
Padded headband and foam-filled ear cushions. Coiled 8-ft. cord. Wt. 16 oz.

Sony DR-9-Stereo dynamic headphone. Impedance 8 ohms, frequency response 30-18k Hz. Maximum input power .2 watt. Stereo/mono switch, slide-type volume and tone controls for each channel. Padded headband and ear cushions. With 15-ft. cord. Wt. 18 oz.

Sony DR-11 - Stereo dynamic headphone. Impedance 8 ohms, frequency response 20-28k Hz. Maximum input power .2 watt. Stereo/mono switch, slide-type volume and tone controls for each channel. Padded ear cushions. With 6-ft. cord. Wt. 13 oz.

Sony DR-41 - 4-channel/stereo dynamic headphone. Impedance 4-16 ohms, frequency response 20-20k Hz. Maximum input power .1 watt. 4-channel/stereo switch. Padded ear cushions. With 6-ft. cord. Wt. 1212 oz.

Sony ECR-500 - Stereo electrostatic headphones. Impedance 30 ohms, frequency response 20-20k Hz. No external power supply needed. Adaptor unit has speaker/headphone switch. Padded headband and ear cushions. With 6-ft. cord. Headphone wt. 12 oz., adaptor wt. 214 lbs.

Superex
Superex Classic CL-1 - Stereo dynamic headphone. Impedance 35 ohms, frequency response 20-20k Hz, distortion 0.2 per cent at 110 dB. Padded headband, foam-filled ear cushions. Coiled 15-ft. cord with clothing clip. Wt. 1012 oz.

Superex EP-5 - Stereo electrostatic/ dynamic headphone. Frequency response 10-24k Hz. Each earpiece contains two-way system consisting of electrostatic tweeter and dynamic woofer. Control consule has speaker/ headphone selector switch. Foam-filled ear cushions. Coiled 1 5-ft. cord.

Superex PEP-77E - Stereo electrostatic headphone, impedance 4-1 6 ohms, frequency response 1 5-1 8kHz±2 dB. Requiresminimum driving power 5 watts per channel. With PEP control console containing self energizing/ac modes, volume level controls, speaker switch and output for two sets of headphones. Foam-filled ear cushions. Coiled 15-ft. cord. Headphone wt. 1 2 oz. Control unit housed in walnut-finish wood cabinet. Size 1 1 x3]Ax6Y2 in.

Superex PEP 79E - Stereo electrostatic headphone. Same as PEP-77D except has Superex CC-79 control console with connections for one set of headphones in self-energizing mode and no auxiliary controls. Console housed in vinyl covered metal case. Size 7x2/2x4 in. With 220 volt adapter.

Superex Pro VII - Stereo dynamic headphone, impedance 4-16 ohms, frequency response 1 5-23k Hz. Maximum power input 2 watts. Each earpiece contains a two-way system with separate woofer and tweeter. Padded headband and foam-filled ear cushions. Coiled 15-ft. cord. Wt. 18oz.

Superex QT-4B - 4-channel dynamic headphone. Impedance 4-1 6 ohms, frequency response 20-18k Hz. Maximum power input 0.5 watts. Foam-padded headband and ear cushions. Stereo/4-channel mode switch. Coiled 15-ft. cord. Wt. 16 oz.

Superex TL-3 - Stereo dynamic headphone. Frequency response 25-20k Hz. Foam-type ear pads. Coiled 1 5-ft. cord.

Superex 930 - Stereo dynamic headphone.
Frequency response 40-14.5 k Hz. Foam-filled ear cushions. With 7-ft. cord.

Teac
Teac HP-100 - Stereo dynamic headphone. Impedance 8-16 ohms, frequency response 1 5-20k Hz. Maximum input 0.5 watts. Foam-typeearpads.Coiled 13-ft. cord.

Teac HP-101 - Stereo dynamic headphone, impedance 8 ohms, frequency response 18-20k Hz. Maximum power input 0.5 watt. Padded headband and foam-filled ear cushions. Coiled 6/2 -ft. cord. Wt. 1 3.5 oz.

Technics
Technics EAH-80 - Stereo electrostatic headphone. Impedance 4-16 ohms (with adapter), frequency response 20-20k Hz. Maximum distortion 0.8 per cent. (101 dB spl). Maximum input 5 volts rms. Tansducers are electret-type units requiring no bias potential. Foam-filled ear cushions. With 6.5-ft cord to adapter unit. Headphone wt. 1 2 oz. Adapter unit contains volume control.

Technics EAH-420 - 4-channel/stereo dynamic headphone. Each earpiece contains separate tweeters for front and rear channels and one woofer. Loudness and tone controls for each earpiece. 4-channel/stereo mode switch.

Toshiba
Toshiba HR-40 - 4-channel/stereo dynamic headphone, impedance 4-1 6 ohms, frequency response 20-20k Hz. Maximum power input 0.3 watt. 4-channel/stereo switch. Padded headband and foam-filled ear cushions. Two coiled 6.5-ft. cords. Wt. 27.5 oz.

Toshiba HR-50 - Stereo dynamic headphone, impedance 4-1 6 ohms, frequency response 20-20k Hz. Maximum power input 0.25 watt. Cross-field/binaural switch. Padded headband and foam-filled ear cushions. With 6V2-ft. cord. Wt. 20.3 oz.

Toshiba HR-80 - Stereo dynamic headphone, impedance 4-50 ohms, frequency response 20-20k Hz. Maximum power input 0.25 watt. Cross-field/binaural switch. Foam-filled ear cushions. With 6/2-ft. cord. Wt. 13 oz.

Toshiba HR-700 Stereo dynamic head phone. Frequency response 20-22k Hz. Bass, treble and volume controls on each earpiece. Padded headband, ear cushions. Coiled 10-ft. cord. Wt. 28 oz.

Wharfedale
Wharfedale DD1 - Stereo dynamic headphone with separate woofer and tweeter in each earpiece. Impedance 8-16 ohms, frequency response 1 6-22k Hz+3 dB. Harmonic distortion 1 per cent. Padded adjustable headstrap and removable foam-filled vinyl ear cushions. Coiled 15-ft. cord. Wt. 22 oz.

Wharfedale Isodynamic - Stereo isodynamic headphone, impedance 120 ohms, frequency response 30-20k Hz ±2.5 dB. Maximum input 25 volts RMS. Maximum distortion 0.1 per cent. Transducer is electrically-conductive, magnetically-moti-vatea membrane. Padded headband and foam-filled ear cushions. Coiled 10-ft. cord, and special adapter for connection directly to amplifier speaker terminals. Wt. 16 oz.
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