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Linn Tukan loudspeaker Measurements

Sidebar 3: Measurements

The Tukan's measured sensitivity of 86.5dB will make it a bit easier to drive than the Aerial 5. This sensitivity is 2dB higher than the 5's—a difference roughly equivalent to that between 45Wpc and 70Wpc amplifiers. The impedance minimum (fig.1) is a not-too-cruel 4.6 ohms, with most of the band keeping above 6 ohms. The port tuning at 57Hz is accompanied by a dip in the impedance curve. The slight wrinkle in the curve at 28kHz is due to the ultrasonic tweeter resonance.

Fig.1 Linn Tukan, electrical impedance (solid) and phase (dashed) (2 ohms/…

Mark Levinson No.39 CD player

My next-door neighbor bought a late-'70s Porsche 924 last week, and I'm really glad he did. For one thing, it adds a little class to the 'hood—my 1984 Grand Wagoneer's peeling "wood paneling" is far more typical of the vehicles in my part of town. And Eric is just so obviously thrilled to own a piece of the legend—a real Teutonic driving machine.

"The 924 is a baby Porsche," pooh-poohed John Atkinson when I told him about Eric's new ride. And he's right—it's not a racing machine. The 924 was designed to appeal to a new Porsche customer—one who couldn't afford their "grown-up" cars, or…

Monster Power AVS 2000 Automatic Voltage Stabilizer & Equi=Tech 2Q & Q650 Balanced Power Systems Page 3

Martin Glasband didn't invent balanced power, nor is he the only person to employ it. But Glasband was probably among its earliest and most vocal champions in the pro sound/high-end audio industry, bringing deep insights into its practical applications and creative refinements, including a number of patents for the bifilar winding of balanced power transformers—which is what puts the sonic performance of Equi=Tech products in a class by themselves.

Balanced power defines the ground reference in a manner that cancels noise. Normally, you have 120V on the hot lead and 0V on the neutral…

Monster Power AVS 2000 Automatic Voltage Stabilizer & Equi=Tech 2Q & Q650 Balanced Power Systems Associated Equipment

Sidebar 1: Associated Equipment

Analog sources: Rega Planar 25 turntable, Rega RB600 tonearm, Grado Statement Master cartridge, Marantz PMD430 portable cassette recorder.
Digital sources: California Audio Labs Delta CD transport, Alpha 24-bit/96kHz DAC, and CL-20 DVD-V/CD player; Sony SCD-777ES SACD/CD player.
Preamplifiers: Musical Fidelity Nu-Vista, VTL 5.5, Rogue Audio Magnum 99, Rogue Audio Stealth phono preamp.
Power amplifiers: Musical Fidelity Nu-Vista 300, Mesa Baron, Rogue Audio Magnum M-120, VTL MB-450.
Loudspeakers: Joseph Audio RM33si Signature & RM7si…

Monster Power AVS 2000 Automatic Voltage Stabilizer & Equi=Tech 2Q & Q650 Balanced Power Systems Specifications

Sidebar 2: Specifications

Monster Power AVS 2000 Automatic Voltage Stabilizer: Servo-controlled variable voltage transformer with microprocessor controller and electronic shutdown on over/undervoltage or overcurrent. Two unswitched, four switched-timed outputs. Accepts 3-30V triggers for remote turn-on capability in custom installations. Voltage range: 80-140V output voltage at 120V RMS input. Sinewave: 339.5V P-P (±1% of regulation). Operating temperature: 40-95 degrees F.
Dimensions: 17" W by 7.75" H by 13.75" D. Weight: 68 lbs.
Serial number of unit reviewed: 00012.
Price: $…

Recording of August 1995: Pärt: <I>Fratres</I>

PÄRT: Fratres
Fratres for strings & percussion; Fratres for violin, strings, & percussion; Fratres for wind octet & percussion; Fratres for eight cellos; Fratres for strings; Fratres for string quartet; Fratres for cello & piano. Plus: Cantus in Memory of Benjamin Britten, Summa, Festina Lente
Rudolf Werthen, I Fiamminghi (The Orchestra of Flanders)
Telarc CD-80387 (CD only). James Mallinson, prod.; Jack Renner, Tony Faulkner, engs. DDD. TT: 79:00

Arvo Pärt is perhaps the only true "minimalist." Rather than endlessly proliferating arpeggios à la John Adams,…

Ayre Acoustics V-3 power amplifier

"Why no review of the Ayre V-3?" queried Stephen Slaughter in July's "Letters" column, echoing several urgent posts to my e-mail address. Word of mouth on this remarkable 100Wpc amplifier was reaching fever pitch. Show reports over the last several years had sounded a consistent note—rooms that demoed with V-3s kept getting mentioned in "Best of Show" overviews. Naturally, this also meant that the pendulum had started its backward swing. "It's not really as good as people are saying," one WCES attendee confided in me. "That's why they won't give it to critics."

I knew this last one to be…

Ayre Acoustics V-3 power amplifier Page 2

"No one uses choke input filters anymore because they're just too expensive. But they have two big advantages—the first is that you get better AC filtration. The second is that an inductive choke resists changes in current—just as a capacitor resists changes in voltage—so it slowly releases current as its magnetic field collapses. This avoids that 120Hz spike of current going into the cap. Presumably, in a typical design, the capacitor filters this out. However, it's generating HF harmonics all through the audio band before it even gets to the cap, so garbage is radiated through the wiring…

Ayre Acoustics V-3 power amplifier Page 3

Don't read this as an indictment of MIT's AC-conditioning products. Though I haven't used them for long, or in many systems yet, I have heard them improve the sound of other gear; so I can't really can't generalize. What I think I was hearing with the Ayre/Krell combo was the payoff for all of the attention paid to the power supplies.

Just to show you what a fun job this can be sometimes, I had two other AC conditioners around the house—Transparent Audio's Powerlink HPAV and API's Power Wedge 112—and neither of them afforded any improvement in the sound, either. Nor did high-end IEC…

Ayre Acoustics V-3 power amplifier Page 4

"When we were building different prototypes, we measured this design and it didn't measure great—it measured okay, but nothing spectacular. So we tried putting a source-follower driver stage on the cascode's output and it measured fantastic! The bandwidth went up and HF distortion dropped, but it didn't sound as good. So we scrapped it and came back to this design. How different did they sound? It was like the difference between a mass-market receiver and Jadis separates!

"I don't think it's because we limited the bandwidth; I suspect it has to do with adding that extra stage."

…