Dan D'Agostino: I took the best parts of the Momentum's more sophisticated and complex circuitry and put them in the Progression, without using the same high parts count. Each stage of the Momentum's gain amplifier is separate, with input stage and driver stages on separate rails. All of the…
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To accompany my review of the Dan D'Agostino Master Audio Systems Progression monoblock amplifier elsewhere in this issue, I talked to Dan D'Agostino about the amplifier's design. I started by asking him what were some of the major differences between the Momentum and the Progression monoblocks?
For as long as I've known about high-end audio, I've put Dan D'Agostino, co-founder of Krell, on the same pedestal reserved for the likes of Frank McIntosh, Saul Marantz, Avery Fisher, H.H. Scott, and Sidney Harman. The reason is simple: Dan's the man whose achievements at Krell led me from the harsh sound of my first high-end amp into another dimension, one of truly musical sound reproduction.
I still recall the layout of the room where I first met D'Agostino—at an audio show, years before I began writing for Stereophile. I introduced myself in a trembling, fan-boy voice. (I did the same…
Returning to Morlot and Seattle's Rite, I confirmed that while the sound was a touch warmer than neutral higher in the range, timbres were absolutely believable with timpani and bass drum. Further listens to recordings of percussion, cello, and double bass confirmed that, through my Wilson Audio Alexias, the Progressions excelled at conveying low pitches with more tonal accuracy than I was accustomed to.
I also began to realize that while my reference Pass Labs XA 200.8 monoblocks sound gorgeous, and convey a special glow around the edges of each note, the Progressions illuminated each…
Sidebar 1: Specifications
Description: Solid-state monoblock power amplifier using bipolar output devices. Input: 1 balanced (XLR). Power output: 500W into 8 ohms (27dBW), 1000W into 4 ohms (27dBW), 2000W into 2 ohms (27dBW). Frequency response: 1Hz–200kHz, –1dB; 20Hz–20kHz, ±0.1dB. Voltage gain: 30dB. Input impedance: 100k ohms. Output impedance: 0.15 ohm. THD, 1kHz at 500W into 8 ohms: <0.15%. Signal/noise: 105dB, unweighted.
Dimensions: 18" (460mm) W by 7.5" (190mm) H by 20" (510mm) D. Weight: 150 lbs (68kg).
Finishes: Black, Silver.
Serial numbers of units reviewed:…
Sidebar 2: Associated Equipment
Digital Sources: dCS Paganini SACD/CD transport & Rossini DAC & Scarlatti Clock; Oppo Digital BDP-93 NuForce Edition universal BD player; Apple MacBook Pro with Intel i7, SSD, 8GB RAM; external hard drives, USB sticks.
Power Amplifiers: Pass Labs XA200.8 monoblocks.
Loudspeakers: Wilson Audio Specialties Alexia.
Cables: Digital: AudioQuest Diamond (FireWire, Ethernet), Wireworld Platinum Starlight Ethernet, Nordost Odin 1 & 2 & Valhalla 2 (USB). Interconnect, Speaker, AC: Nordost Odin 2.
Accessories: Grand Prix Monaco rack…
Sidebar 3: Measurements
I initially measured one of the Dan D'Agostino Master Audio Systems Progression Mono monoblocks (serial no. PMO26P) with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). Before doing any testing of a power amplifier, I precondition it by running it at one-third its specified power into 8 ohms for 60 minutes. This power level results in the highest thermal stress on the output devices of an amplifier having a class-B or class-AB output stage. After an hour driving 167W into 8 ohms, the temperature of the Progression's top panel and heatsinks…
It was almost exactly a year ago that I first heard Cecile McLorin Salvant at the Village Vanguard. I came home and wrote a blog for this space, wondering how I could have missed her ascent (she'd already won a Grammy and other prizes) and deeming her the best jazz singer around, standing among the greats of all time. I went back to see her, dragging along my wife and two friends, the following Sunday—the late set, the final set of his week-long stint—and she was better still. (That set inspired me to pitch a profile of her to The New Yorker, which was published this past May.)
As it…
Hef is gone and whether you think he was a villain, a visionary or a skeezy old fool, the news, alleged by his widow and some recent former girlfriends was shocking: Hefner, who let’s not forget was 91 when he died, had taken so much Viagra that may have experienced a rare side effect and lost his hearing. In other words, he’d chosen sex over music.
You can debate the merits of that trade, but what was weird was that Hefner had always been such a music fan, supporting jazz in particular.
I interviewed for an editorship with Playboy many years ago, and all during the interview…
Starting with Musicians As Audiophiles subject #1, jazz drummer extraordinaire Billy Drummond, one thing soon became clear: New York City and its environs are a veritable smorgasbord of musicians who value high-end audio authenticity as much as any longtime reader of Stereophile. Billy Drummond led us to such like-minded audiophile/musicians as bassists Chris Lightcap and John Hébert, drummer Dan Weiss, guitarist Adam Rogers, and preeminent music scholar and jazz superstar Ron Carter.
"A fellow drummer and friend, Aaron Kimmel, got me into audio via Billy Drummond," notes MAA #7, drummer…
A revitalized Rocky Mountain Audio Fest begins this Friday, October 6, in the completely renovated Denver Marriott Tech Center Hotel. The three-day show, which opens to the public at noon on Friday, promises 143 active exhibit rooms that will host 358 exhibitors from 27 countries and 36 states. In addition, the show's widely lauded Canjam will host an additional 64 exhibitors within its walls, and seven more large exhibits in the lobby. Exhibit numbers would have been even greater, had not a few exhibitors lost everything in the recent hurricane onslaught.
These impressive figures place…