I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Revel Performa F228Be's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield responses. (I left off the grilles for the measurements.) My estimate of the F228Be's voltage sensitivity was 89.1dB/2.83V/m, slightly below the specified 90dB/2.83V/m but within the margin of error. The impedance magnitude remains below 8 ohms for the entire midrange and bass, with minimum values of 3.42 ohms at 98Hz and 3.55 ohms at 290Hz (fig.1). There is also a demanding…
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Saturday, January 26, 5–9pm, The Audio Guy (1590 E. Business 121, Building 2, Suite 500, Lewisville, TX 75056) is having an open house with VPI Industries president Mat Weisfeld, who be giving a sneak peek at the new limited-edition HW40 turntable. Michael Vamos will be on hand to demo the GamuT RS5i speakers and other vendor reps will also demonstrate some of their latest offerings. And singer/songwriter Robynn Shayne will be performing some of her latest music!
There will be music, food, fun, drinks, and giveaways. RSVP to clay@audioguydfw.com.
Roon, one of the major brands of audiophile-quality high-resolution music playback software, has just released its v.1.6 upgrade. Roon 1.6 finally includes a portal for hi-rez streaming Qobuz, whose US launch is rumored for sometime next month. In addition to pairing Roon's rich metadata with the entire Qobuz and Tidal catalogs, the upgrade also offers major new features.
Among other improvements, when you choose to play a recording that's in your personal library, Roon now displays identical or similar tracks on Qobuz and Tidal. As before, it's easy to click on a little glowing purple…
I've just returned home from one of the greatest concerts of my life, and felt absolutely compelled to share my thoughts with you. Yo-Yo Ma performed all six of J.S. Bach's Cello Suites, from memory, over a mesmerizing two-and-a-half hours at Red Rocks Amphitheatre, in Morrison, Colorado. It was a truly special experience.
When I was eight, Yo-Yo Ma was my inspiration to pick up the violin. I have over a dozen of his recordings in my collection. My copy of his 2001 recording of the Bach Cello Suites 1, 5, and 6 (CD, Sony Classical 89796) is so worn that the CD case is falling apart. I am…
To audio designers in Japan and elsewhere, the single-ended, 300B-tubed amplifier is like a haiku: an art form defined by both its prescribed limitations and the potential such restraint offers for artistic expression. Here, the only hard-and-fast rule is a simple one: output devices are limited to one 300B directly heated triode tube per channel. From there, it's a blank slate: Do you want AC or DC on the output-tube heaters? Tube or solid-state rectification? Low or high gain? Fixed or cathode bias? New parts, vintage parts, or a mix of both? Triode or pentode tubes as drivers? Capacitors…
Culshaw's Rheingold, made in 1958, was the first recording to exploit stereo technology's ability not only to reproduce the spatial characteristics of a recorded performance, but to re-create, for the listener, spatial effects created entirely in the studio, including the singers' relative positions on an imaginary stage and their movements across that stage as they perform. Through the Air Tight, that stage was notably larger than through most amps; indeed, it was considerably larger than with other tube amps of my experience that use negative feedback—something I associate with amps whose…
Sidebar 1: Specifications
Description: (100V version): Tube complement: two 300B, two 12AU7, two 12BH7, one 5U4BG. Power output: 9Wpc at 5% THD (9.54dBW). Input sensitivity: 290mV at full output. THD: <1% (1kHz/1W/8 ohms). Damping factor: 7 (1kHz/1W/8 ohms). Frequency response: 25Hz–40kHz, –1dB/1W.
Dimensions: 16.9" (430mm) W by 9.65" (245mm) H by 10.8" (275mm) D. Weight: 54 lb (24.5kg).
Serial number of unit reviewed: 30005D.
Price: $16,995 with Electro-Harmonix 300B tubes; $19,995 with Takatsuki 300B tubes; $15,995 without 300B tubes. Approximate number of dealers: 18.…
Sidebar 2: Associated Equipment
Analog Sources: Garrard 301, Thorens TD 124 turntables; EMT 997, Sorane ZA-12 tonearms; EMT TSD 15, Ortofon SPU A Wood, Shindo SPU pickup heads; EMT TSD 15 N sph, Koetsu Onyx Platinum, Denon DL-103 cartridges.
Digital Source: Sony SCD-777 SACD/CD player, Mytek Liberty D/A processor.
Preamplification: Auditorium 23 Hommage T1 & T2 step-up transformers, Shindo Laboratory Monbrison (2017) preamplifier.
Power Amplifiers: Cary Audio CAD-805RS monoblocks, Shindo Laboratory Haut-Brion.
Loudspeakers: DeVore Fidelity Orangutan O/93.
Cables:…
Sidebar 3: Measurements
I measured the Air Tight ATM-300R with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). Before doing any testing, I checked the ATM-300R's front-panel meter to ensure that the bias was correctly set for the two 300B output tubes.
The Air Tight's maximum voltage gain into 8 ohms from its High (8 ohm) output-transformer tap, which was how Art Dudley listened to the amplifier, was a high 29.5dB; from the Low (4 ohm tap) it measured 26.9dB. Both output taps preserved absolute polarity (ie, were non-inverting). The input impedance was a…
There are many ways to talk about the remarkable Symphonies Nos.1 & 4 Jeux vénitiens of Polish composer Witold Lutoslawski (1913–1994). You could, for example, approach them as does Kimmo Korhonen, whose extremely detailed and well-thought-out liner notes for the recent Ondine SACD of these works from Hannu Lintu and the Finnish Radio Symphony Orchestra examine the evolution of Lutoslawski's tonal language and explain that they basically represent the beginning (Symphony No.1, 1947), middle (Venetian Games, 1960–1961) and end (Symphony No.4, 1992) of his arc as a mature composer. Or you…