Digital Source: Ayre C-5xe universal player.
Preamplifiers: Ayre KX-R, Conrad-Johnson ACT2 Series 2.
Power Amplifiers: Ayre MX-R monoblocks, Musical Fidelity Nu-Vista 300.
Loudspeakers: Avalon Indra, Wilson Audio Systems WATT/Puppy 8.
Cables: Interconnect: Shunyata Research Aries & Antares, Stealth Indra & Nanofiber. Speaker: Shunyata Research Anaconda & Orion, Stealth Dream.
Accessories: Ayre L-5xe AC filter, Furutech eTP-609 distribution box; OSAR equipment stand; Furutech RDP panels, RealTraps Mini & Mondo Traps.—Wes…
search
Sidebar 2: Associated Equipment
Sidebar 3: Measurements
The Thiel CS3.7's voltage sensitivity is specified as 90dB/2.83V/m. My B-weighted estimate on its tweeter axis, assessed with DRA Labs' MLSSA system, was slightly above that figure, at 90.7dB(B)/2.83V/m. This may well have been affected by the Thiel's frequency response (see below). The sensitivity is usefully higher than average, which is a good thing considering that the CS3.7's impedance remains between 2 and 3 ohms over much of the audioband (fig.1), and that there is a demanding combination of 3.8 ohms and –40° capacitive phase angle at 60Hz. Thiel specifies…
Musical Fidelity's "Supercharger" concept is simple, which is perhaps why no one had thought of it before: If you love the sound of your low-powered amplifier but your speakers are insensitive, or you just need more loudness, you insert the high-power Supercharger amplifier between your low-powered amp and speakers. The Supercharger loads the small amplifier with an easy-to-drive 50 ohms, and, in theory, has so little sonic signature itself that it passes on the sonic signature of the small amp unchanged, but louder.
Michael Fremer reviewed Musical Fidelity's first Supercharger amplifier…
Looking back at what I've written, I seem to have concentrated on the 750K's abilities to play loudly and cleanly—which they indeed did. But for all their ability to kick loudspeaker butt, the Musical Fidelity could still do delicacy with aplomb. Robert Plant and Alison Krauss's Raising Sand (CD, Rounder 11661-9075-2) has been in heavy rotation chez Atkinson since I picked it up while killing time at a Starbucks a year ago. The double bass on this disc can be problematic with some amplifier-loudspeaker combinations, as its considerable midbass energy demands an amplifier capable of retaining…
Sidebar 1: Specifications
Description: Solid-state, monoblock power amplifier with balanced and unbalanced line-level inputs and 1 pair speaker-level inputs. Maximum power output: 750W into 8 ohms (28.75dBW), 1150W into 4 ohms (24.7dBW). Maximum output voltage: 78V RMS, 20Hz–20kHz; 222V peak–peak. Maximum current: 250 amps peak–peak. Frequency response: 20Hz–30kHz, +0/–0.2dB. THD+noise: <0.01%, 20Hz–20kHz. Damping factor: 220. Input impedance: 50k ohms (line), 50 ohms (speaker). Input sensitivity for full power out into 8 ohms: 2.5V (line), 35V (speaker). Signal/noise (no reference…
Sidebar 2: Associated Equipment
Digital Sources: Ayre C-5xe universal player; Cary Audio Design 306 Pro SACD player; PrimaLuna ProLogue Eight CD player; Mark Levinson No.30.6, Benchmark DAC 1 USB D/A converters; Logitech (Slim Devices) Transporter WiFi music player with Apple Mac mini for media storage.
Preamplifiers: Mark Levinson No.380S, Simaudio Moon Evolution P7, Ayre KX-R.
Power Amplifiers: Mark Levinson No.33H, Ayre MX-R, Parasound Halo JC 1, Musical Fidelity 550K Supercharger (all monoblocks).
Loudspeakers: PSB Synchrony One, Dynaudio Sapphire, Totem Model 1 Signature,…
Sidebar 3: Measurements
I examined the Musical Fidelity's measured behavior primarily using Stereophile's loaner sample of the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com); for some tests, I also used my vintage Audio Precision System One Dual Domain.
My first test of an amplifier is to run it for 60 minutes at one-third its specified power into 8 ohms, which is thermally the worst case for an amplifier with a class-B or -AB output stage. The 750K got very hot very quickly, its cooling fans turning on after two minutes, its…
The Gini Systems "LS3/5a" is an unlicensed and inexact replica of the celebrated LS3/5a outside (remote location) broadcast monitoring loudspeaker originally developed by the BBC in the early 1970s. (For a précis of the LS3/5a's history, click here.)
Stereophile reviewed the BBC's 1977 version of the LS3/5a in March of that year. The directory at the bottom of the webpage devoted to that review provides links to coverage of later self-proclaimed LS3/5a incarnations, but not to speakers such as Harbeth's HL-3PES-2, which, although designed as drop-in replacements for BBC-spec LS3…
Sidebar 1: Specifications
Description: Two-way, sealed-box stand-mounted loudspeaker. Drive-units: 1" soft-dome tweeter, 5" plastic-cone woofer. Frequency range: 50Hz–20kHz. Nominal impedance: 8 ohms. Power handling: 50Wpc.
Dimensions: 12" W by 7.5" W by 6.25" D.
Serial Numbers of Review Samples: 06070025A & B.
Price: $490/pair in kit form, $560/pair assembled.
Manufacturer: Gini Systems, Inc., 3431 Pomona Blvd., Unit G, Pomona, CA 91766. Tel: (909) 720-8188. Web: www.gini.com.
Sidebar 2: Measurements
As John Marks writes, he sent me this unauthorized copy of the classic BBC-designed minimonitor to measure because he suspected an internal wiring problem in one of the speakers. This turned out to be the case: as you can see in fig.1, which shows the step responses of both samples, while both speakers had the tweeter wired in inverted acoustic polarity, one speaker also had the woofer wired in negative polarity (red trace) rather than positive (blue trace). Having the woofer and tweeter in the same polarity results in a suckout in the crossover region between the…