Sidebar 3: Measurements
I used DRA Labs' MLSSA system to measure the Totem Skylight's farfield behavior with a calibrated DPA 4006 microphone. For the speaker's nearfield responses, I used an Earthworks QTC-40 mike, which has a small, ¼"-diameter capsule that doesn't obstruct the sound from the woofer or port.
Totem specifies the Skylight's sensitivity as "88dB," presumably for 1W at 1m. My estimate was 85.4dB(B)/2.83V/m, which is about what I would anticipate from such a small loudspeaker and 1dB higher than that of the KEF LS50. However, while the Totem Skylight's nominal…
Soon after I took over preparing Stereophile's biannual Recommended Components listing from the magazine's founder, J. Gordon Holt, in 1986, I ran into a problem. With so many products listed, the magazine was running out of the necessary pages to include them all (footnote 1). To solve this problem, I looked at how long a typical product remained on the market before being updated or replaced. The answer was 3–4 years. I therefore implemented a policy that unless one of the magazine's editors or reviewers had continued experience with a product, it would be dropped from Recommended…
The bass guitar and kickdrum were reproduced with appropriate force and definition, though I felt I needed to remove the plugs from the Minos' upper ports to optimize the system's low-frequency reproduction. Mark Knopfler's vocalizing sounded clean and appropriately husky. But what really enthralled me about this atmospheric track was the depth of the soundstage. Some of the instruments had been mixed with various amounts of reverb. The piano that accompanies the acoustic guitar at the beginning before the verse, for example, was set way back in the soundstage, behind the voice and marimba…
Sidebar 1: Specifications
Description: Solid-state, class-AB monoblock power amplifier. Inputs: 1 single-ended (RCA), 1 balanced (XLR). Outputs: 1 single-ended (RCA), 1 balanced (XLR) pass-through loop for multiamping; 2 pairs five-way binding posts. Power output: 450W into 8 ohms (26.5dBW), 850W into 4 ohms (26.3dBW), 1300W into 2 ohms (25.1dBW). Class-A output power: 25W (high bias), 10W (low bias). Current capacity: 180A peak. Frequency response: 20Hz–20kHz, +0/–0.25dB; 2Hz–120kHz, +0/–2dB. Voltage gain: 29dB or 23dB, switchable. Input impedance: 50k ohms (unbalanced), 100k ohms (…
Sidebar 2: Associated Equipment
Analog source: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B cartridge, Channel D Seta L phono preamplifier.
Digital sources: Roon Nucleus+ file server; Ayre Acoustics C-5xeMP universal player; PS Audio PerfectWave DirectStream and Mark Levinson No.30.6 D/A converters; Ayre Acoustics QA-9 A/D converter.
Preamplifier: Parasound Halo JC 2.
Power amplifiers: Parasound Halo JC 1 and Lamm Industries M1.2 Reference (both monoblocks).
Loudspeakers: Vimberg Mino; KEF LS50.
Cables: Digital: AudioQuest…
Sidebar 3: Measurements
I tested the Parasound Halo JC 1+ with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I preconditioned the amplifier by operating it at one-third the specified power into 8 ohms for an hour with the output-stage bias set to Normal. (With a class-AB output stage, one-third power results in the maximum dissipation in the output devices.) At the end of this time, the side-mounted heatsinks were hot, at 116.7°F (47.1°C). The top panel was a little cooler, at 98.9°F (36.7°C).
The Parasound's voltage gain into 8 ohms, set to Normal,…
I loved New Orleans music before I even knew what it was.
In the mid-1960s, I went to high school in Williamsburg, Brooklyn, which back then was a bleak, On the Waterfront landscape of dock workers and drifters hanging out in the pool halls along Bedford Avenue. We were warned to watch out on our way to track practice at nearby McCarren Park, because the pool halls were violent and confrontations often spilled out onto the street.
Around the corner from school was a small soda fountain, where I would hang out and play the Wurlitzer jukebox. It was my first audiophile-level…
Designing Audio Power Amplifiers, Second Edition, by Bob Cordell, Routledge/Focal Press, 2019. 776pp. $160.00, hard cover; $97.95, paperback.
I first met Bob Cordell at clinics he gave at the last audio show Stereophile organized, Home Entertainment 2007, in Manhattan. At those clinics, Bob shared his views on why amplifier measurements are not always good at predicting differences in sound quality. So when I was scheduled to host a seminar—"Amplifiers: Do Measurements Matter?"—at this year's now-canceled AXPONA, Cordell was on the short list of designers I felt would offer valuable…
"What happens in college stays in college" might be the best policy for most undergrad-formed bands, but Snarky Puppy is an exception to that rule (and a number of others). Bassist/composer Michael League found fertile musical ground in the jazz studies program at the University of North Texas when he formed Snarky Puppy in 2003. The band thought big from its inception as a 10-piece group and has continued to morph and shapeshift to the present, living out of vans, paying dues, relentlessly gigging, and garnering three Grammys along the way. In 2017, the group was tagged jazz group of the…
Matson: Let's get to musical influences and sources. What about Frank (Zappa)?
League: My dad was a huge Zappa-head. It was in the house. On Christmas day, instead of listening to Christmas carols, we listened to Apostrophe (Zappa Records ZR 3851C LP 2018). I heard Zappa so much as a kid that I never really went down the hole with him as an adult, though I love him. He's less of an influence on Snarky Puppy than some people think.
Matson: The whole jazz-fusion thing?
League: People bring up Mahavishnu or Return to Forever as influences. But they're actually not…
