Sidebar 3: Measurements
I performed a full set of measurements on the Air Tight ATM-1S, using my Audio Precision SYS2722 system (see www.ap.com and the January 2008 "As We See It). Before I did any testing, I let the amplifier run for an hour with a 1kHz tone at 1Wpc into 8 ohms, then turned off the input and checked that the bias current for each of its four output tubes had been correctly set. I used the rear-panel inputs for the testing, and repeated some tests using the front-panel input jacks to see if there were any differences. There weren't.
As Art Dudley surmised, the…
Can a power-supply upgrade produce audible sonic benefits? If you've upgraded the power supply of a phono preamplifier, you probably don't need to be convinced that it does, and those usually cost only a small percentage of the price of the model they power. But to add Simaudio's Moon Evolution 820S power supply ($8000) to the Moon Evolution 650D DAC–CD transport ($9000), which I reviewed in the November 2011 issue, almost doubles the latter's cost—though the 820S can be used to simultaneously power two Moon Evolution components, like the 750D DAC ($14,000), 740P preamplifier ($9500), and…
Adding the 820S immediately produced a substantially improved and more inviting sound that, rather than to dissect and analyze, I just enjoyed and chalked up to "improved listenability with fewer digital irritants." And after living with the 820S for a few months, removing it made the differences even more pronounced—glaringly so.
In general, adding the 820S tightened the bottom end and removed smear and edge from the top, while improving high-frequency extension and the sense of air around instruments. Instrumental three-dimensionality improved, and microdynamics were particularly…
Sidebar 1: Specifications
Description: Outboard power-supply upgrade for selected Simaudio Moon Evolution models. Transformers: two, 0.25kVA each. Total capacitance: 80,000µF. Total inductance: 80mH. Output voltages: ±20V (analog supply, output 1), ±14V (digital supply, output 2). Power consumption at idle: 25W. AC power requirements: 120V/60Hz or 240V/50Hz.
Dimensions: 18.75" (480mm) W by 4" (103mm) H by 16.81" (431mm) D. Shipping weight: 40 lbs (18.2kg) shipping.
Serial number of unit reviewed: P8823170.
Price: $8000. Approximate number of dealers: 80. Warranty: 10 years,…
Sidebar 2: Associated Equipment
Analog Sources: Continuum Audio Labs Caliburn turntable & Cobra tonearm & Castellon stand; Kuzma 4Point tonearm; Lyra Atlas & Etna, Ortofon Anna & Transfiguration Proteus, Miyajima Labs Zero (mono) cartridges.
Digital Sources: Simaudio Moon Evolution 650D DAC-transport; BPT-modified Alesis Masterlink hard-disk recorder; Meridian Digital Media System; Pure Music, Vinyl Studio music-player softwares.
Preamplification: Ypsilon MC-10L & MC-16L step-up transformers; Ypsilon VPS-100 phono preamplifier; darTZeel NHB-18NS preamplifier.…
It's August as I write this, and I'm looking back at some things that need to be discussed, and forward to the fall audio shows—particularly the 2014 New York Audio Show, which, by the time you read this, will have been held in Brooklyn, September 26–28. I grew up in Brooklyn, not in "the city," Manhattan, a place that we traveled to only for special reasons. Audio shops were rare in Brooklyn—I remember only Audio Exchange—but in Manhattan there was a small cluster near Grand Central Station, there was Lafayette Radio near the Holland Tunnel, a few scattered elsewhere, and the magnet of…
Sidebar 3: Subtle & Not-so-Subtle Changes
During this review I added a variable to the mix: Shunyata Research's new ZTron Alpha Digital AC cable ($995). It's less expensive than the company's top cords, but demonstrably more efficacious for removing power-line noise than some of their earlier, more expensive efforts. Shunyata backed this claim up with a paper-shredder demo at the 2014 Consumer Electronics Show, showing the reduction of AC line noise with an oscilloscope.
Before the 820S's arrival, I'd tried the ZTron Alpha Digital and a stock power cord on the Simaudio Moon…
To use the Mac mini for audio, however, I needed a music program. I had no plans to use iTunes—my prior experience with it was not a happy one. Besides, I require high resolution and multichannel playback, and despite iTunes' convenience, Apple tightly controls its file-format repertoire. I took the easy way out and installed JRiver Music Center/Mac v.19, to take advantage of my experience with Music Center 19 on the PC. It was the right choice—the interface was familiar, and on the first day of use I was able to get it to create libraries of the PCM, FLAC, DSD, and ISO files stored on my…
Sidebar: Contacts
miniDSP Ltd., Unit 1204, Crown Industrial Building, 106 How Ming Street, Kwun Tong, Hong Kong. Tel: (852) 2358-2066. Web: www.minidsp.com.
Meridian Audio Ltd., Latham Road, Huntingdon, Cambridgeshire PE29 6YE, England, UK. Tel: (44) (0)1480-445678. Fax: (44) (0)1480-445686. US distributor: Meridian America Inc., 110 Greene Street, Suite 407, New York, NY 10012. Tel: (646) 666-0140. Fax: (646) 666-0152. Web: www.meridian-audio.com.
Register to win a pair of Vanatoo Transparent One Speakers (MSRP $499.00) we are giving away.
According to the company:
The Vanatoo Transparent One powered speakers set a new price/performance benchmark in the audiophile world. They produce unexpectedly great sound quality (honest, tight bass down to 48Hz!) from small bookshelf speakers that give you a lot of flexibility in how you use them. They are equally at home as a desktop audio system, a music streaming solution for a room where you want music but not stacks of equipment, or as a compact system you take with you…
