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Etymotic Research ER-4S Canal Phone earspeakers Page 2

Where? where?
Etymotic has been making high-quality transducers since 1983, and Mead Killion, the president of the company, has been active in the field of earphones and hearing aids for more than two decades. Killion holds patents on more than 18 different headphone and hearing-aid advances, including the K-AMP amplifier, which revolutionized hearing-aid design.

The ER-4, in fact, is an extension of the design of the Tubephone insert earphone, designed for audiometric research. This device—which placed the transducers in a pack that connected to the ear canal via a 12" hollow tube—…

Etymotic Research ER-4S Canal Phone earspeakers Page 3

But these aren't one-trick ponies. The sound overall is vivid and transparent. Pierre Sprey of Mapleshade, the audiophile recording company, claims that much of the clarity and impact of his productions is due to his custom PZM microphones, which feature capsules with tiny diaphragms—less mass to push, you know. It makes sense; certainly when I listen to his remarkable recordings I'm inclined to believe anything he says on the subject.

Well, the ER-4Ses benefit from that in reverse. These babies are fast! Kendra Shank's Afterglow (Mapleshade 02132 CD) perfectly illustrates both Sprey's…

Etymotic Research ER-4S Canal Phone earspeakers Specifications

Sidebar: Specifications

Description: Dynamic, diffuse-field-response, in-the-ear-canal transducer. Transducer principal: dynamic diaphragm. Frequency response: 20Hz-16kHz ±4dB, 50Hz-10kHz ±2dB. 1kHz sensitivity: 108dB spl for 1V input, 98dB at 1mW. Impedance: 100 ohms, nominal. Maximum output: 115dB spl. Maximum safe continuous input: 3V. Weight: <28gm (1oz). Acoustic polarity: positive (acoustic and electric). Cord length: 4' with 1/8" stereo phone plug. Accessories included: ¼" phone-plug adapter, filter-changing tool, four filters, four extra eartips, shirt clip, carrying pouch.…

Musical Fidelity Tri-Vista kWP preamplifier & Tri-Vista kW Monobloc power amplifier

Thoughts of power, domination, and audio road-rage enter one's mind when contemplating Musical Fidelity's SUV-like, limited-edition, 20th-anniversary offerings (footnote 1). (Only 75 sets of kWPs and kWs will be made.) The gleaming, brushed-aluminum, two-box, oversized, overweight Tri-Vista kWP preamp is fortress-like—the "kWP" looks as if chiseled into the faceplate by grimy, sweaty hands. Each of its boxes weighs almost 56 lbs. The unit's milled-aluminum remote control, the size of a Volkswagen Microbus and looking like something Fred Flintstone might wield, must weigh over 5 lbs. The kWP…

Musical Fidelity Tri-Vista kWP preamplifier & Tri-Vista kW Monobloc power amplifier Page 2

Months later, I'm happy to report that my speakers have not vaporized, though I do behave more cautiously than usual before connecting or disconnecting anything—something reviewers do much more of than most audiophiles. With the kWs, I always mute the system before lowering the stylus to or lifting it from an LP (always a good idea, even with a 3W single-ended triode amp). I mute before changing sources.

When the kWs are powered up, their feet glow first yellow, then, after warmup, blue. The light system seems to go through a full yellow warmup cycle if you power down for even a few…

Musical Fidelity Tri-Vista kWP preamplifier & Tri-Vista kW Monobloc power amplifier Page 3

As one's system improves, cardboard-cutout recordings of musicians can become living, breathing entities. Over the years, and playing the same original pressing, I've been amazed by the transformation undergone by Miles Davis's performances on Kind of Blue: from a reasonable facsimile of a trumpet to one in which the harmonic and textural complexities of air, brass, valves, and lips are laid bare; a recording in which I can virtually "see" the instrument, "feel" it move on and off mike, and sense Davis's lips forming his embouchure.

Cables and power conditioning had enormous effects on…

Musical Fidelity Tri-Vista kWP preamplifier & Tri-Vista kW Monobloc power amplifier Specifications

Sidebar 1: Specifications

Tri-Vista kWP: Tube-transistor preamplifier with separate power supply. Frequency response: 20Hz-30kHz, ±0.5dB. Maximum output voltage: !w55V RMS. Maximum instantaneous output current: 20A peak-peak. Output impedance: <0.1 ohm. Line inputs: Maximum voltage gain: 12.5dB. THD+noise: <0.0027% (5V output, maximum volume). S/N ratio: >98dB ref. 1V output (at half volume, A-weighted). Input sensitivity for 1V RMS output: 240mV. Input impedance: 500k ohms. Overload margin: 35dB for rated input, maximum volume. Channel separation: !w110dB, 20Hz-20kHz, maximum…

Musical Fidelity Tri-Vista kWP preamplifier & Tri-Vista kW Monobloc power amplifier Accessories

Sidebar 2: Accessories

Despite the Musical Fidelity Tri-Vista kW's choke-regulated power supplies, and perhaps because of the amount of current these amplifiers pull, their performance was enhanced to an enormous and quite surprising degree by plugging them into Shunyata Research's entirely passive Hydra 8 power-distribution device ($1995).

During my first month of auditioning the kWs, they drew power from the original Hydra. When I was ready to check out the new Hydra 8, I unplugged the original Hydra and plugged the kWs directly into my dedicated line's Hubbell hospital-grade…

Musical Fidelity Tri-Vista kWP preamplifier & Tri-Vista kW Monobloc power amplifier Associated Equipment

Sidebar 3: Associated Equipment

Analog sources: Simon Yorke Designs S7 turntable; , Immedia RPM2 tonearms; Lyra Helikon Mono, Lyra Titan, Sumiko Blackbird cartridges.
Digital source: Musical Fidelity Tri-Vista and Krell SACD Standard SACD players.
Preamplification: Manley Steelhead, ASR Basis Exclusive, Sutherland PhD phono sections; Halcro dm10, VTL TL-7.5 preamplifiers.
Power amplifiers: Halcro dm68 monoblocks, Musical Fidelity Nu-Vista 300.
Loudspeakers: Audio Physic Avanti III, Wilson WATT/Puppy 7.
Cables: Phono: Hovland Music Groove, Graham IC-70, Cardas Neutral…

Musical Fidelity Tri-Vista kWP preamplifier & Tri-Vista kW Monobloc power amplifier Tri-Vista kW Measurements

Sidebar 4: Tri-Vista kW Measurements

I measured the kW using a separate power supply for each channel. The amplifier offered a slightly higher-than-usual voltage gain of 30.1dB into 8 ohms. It preserved absolute polarity, and its input impedance at 1kHz was a very high 230k ohms. Though this dropped to 166k ohms at 20kHz, the kW's input impedance is so high that it will not load the preamp to any appreciable extent.

The amplifier's output impedance was 0.11 ohm over most of the audioband, rising slightly, to 0.18 ohm, at 20kHz. (Both figures include the series resistance of 6' of…