As you might expect from an amplifier with 12 tubes, the Integrated 1 ran very hot. The line input impedance measured 49k ohms, the phono impedance 30k ohms. Along with its lowish gain of 44dB, this mandates using a moving-magnet cartridge. Maximum voltage gain from the line input was a very high 33dB. Phono overload at 1kHz was high at 100mV. The Integrated 1's line stage and power-amplifer stage invert polarity; the phono stage does not. That means the Integrated 1 is inverting through the phono and line inputs when used as an integrated amplifier or…
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A 50-year-old corroded meter box with aluminum wire.
Rex Hungerford, Edward DeVito, and Craig Bradley rode into town last week and, together with Audioquest's Garth Powell, solved all the electrical problems that have plagued my audio system for years.
Garth Powell, a name familiar to many Stereophile readers, is AudioQuest's electricity guru and designer of the Niagara series of power conditioners; he is also responsible for the company's line of AC and signal cables. Bradley is a local electrician and audio enthusiast who has done electrical work for me in the past, including…
Two circuits would feed a 4-gang AC receptacle box located behind the amplifiers; each amplifier would have its own dedicated 20A circuit. The other two would feed another 4-gang box located behind the equipment rack.
This should have been done 20 years ago when I moved into this house! According to Hungerford's synopsis, the now-corroded electrical infrastructure was assembled in the 1970s and included all-aluminum wire. The subpanel used a decade ago to create the then-new dedicated circuit for the audio system featured 3-wire, metal-clad cabling that does not allow for an isolated…
We audiophiles so frequently get caught up in the pursuit of perfection that some have attempted to rebrand high-end audio as "perfectionist audio." But is it even possible for a single piece of audio gear, let alone an entire audio system, to attain perfection when there's no common agreement as to what "perfection" means? It's easier to cue up a Nirvana track than to find the way to audio nirvana.
Nonetheless, the journey toward sonic perfection continues to grip many of us like a Siren who lures sailors to their death with the sweetness of her song. For some who listen closely and…
After a brief listen, Bill encouraged me to try setting up the Progression M550s and Momentum HD preamp the same way they're set up at D'Agostino's Arizona factory, with the electronics resting on their attached rubber feet. I'd always preferred the effects of aftermarket supports to those rubber feet, but those that sounded best had been discontinued and returned to the distributor. I was curious to learn if returning to the rubber feet might help address some longstanding issues in my system.
During my first listens after Bill departed, I discovered that the lower midrange had lost…
Sidebar 1: Specifications
Description: Solid state class-AB mono power amplifier. Inputs: XLR. Outputs: Custom binding posts. Power: 550W into 8 ohms, 1100W into 4 ohm, 2200W into 2 ohms (all 27.4dBW). Frequency response: 1Hz–80kHz, –1dB; 20Hz–20kHz, ±0.01dB. Input impedance: 100k ohms. Output impedance: 0.1 ohm. S/N ratio: 105dB A-weighted, 75dB unweighted. (These are transposed on the manufacturer's website.) Distortion: 0.15% at 1kHz at 550W into 8 ohms. Power draw at idle: 80W.
Dimensions: 17.875" (454mm) W × 9.0" (230 mm) H × 23" (584mm) D. Weight: 115lb (52.2kg).
Finish:…
Sidebar 2: Associated Equipment
Digital sources: dCS Rossini SACD/CD transport, Rossini DAC, and Rossini Clock; Synology 5-bay 1019+ NAS, Roon Nucleus+ music server, Uptone Audio etherRegen, Small Green Computer Sonore opticalModules (2) and Deluxe opticalModule, Linksys routers (2), and Arris modem, all powered by HDPlex 300 four-component linear power supplies (3) and HDPlex 200 LPS; Apple 2017 iPad Pro and 2017 Macbook Pro laptop with 2.8 GHz Intel i7, SSD, 16GB RAM.
Preamplifier: Dan D'Agostino Momentum HD.
Power amplifiers: Wilson Audio Specialties Alexia 2 with Acoustic…
Sidebar 3: Measurements
For logistical reasons, I measured a different sample of the Dan D'Agostino Master Audio Systems Progression M550 monoblock (serial number PM006P) with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I repeated some of the measurements with the magazine's Audio Precision APx500 analyzer. Usefully, the box included a set of tests performed with the APx500.
Before I performed the testing, I preconditioned the amplifier by running it at one-eighth its specified power into 8 ohms for 30 minutes, as recommended by the Consumer…
I've got a music problem. Specifically, I've got a rock music problem.
It's a true cliché—that is, a cliché that happens to be true: Rock music, in almost all its forms, is young people's music. It's about new, fresh experiences—new love, new sex, consciousness sought or attained, rebellion, drugs—and when you've reached a certain age, those experiences don't feel so fresh anymore. That's a fact about which it's hard not to feel some regret. You don't have to share their sentiment to realize that there's a reason Pete wrote, and Roger sang, "Hope I die before I get old."
Despite…
You've got your 2001: A Space Odyssey speaker, which of course is a tall, black, featureless monolith. Then there's your wooden "Who's buried inside?" speaker, your "R-I-C-O-L-A" speaker, your enema bag or double-inverted enema bag speaker, your menacing hooded-Klansman speaker, your "looks like a robot, praying mantis, or Transformer" speaker (mine), and your "Does it leave a slime trail?" speaker (looks like a snail). You've got your "Is that a room divider?" speaker, your "looks like you stepped on a duck's head" speaker, and your "whipped cream dollop suspended in time" speaker.
That'…