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McIntosh Labs MC2000 power amplifier Measurements part 3

The 1kHz, THD+noise percentage vs continuous output power curves are shown in fig.9. The output is essentially the same at all load impedances, provided the matching output tap is used. The MC2000's discrete clipping levels at 1% THD+noise are shown in Table 1.

Fig.9 McIntosh MC2000, distortion (%) vs continuous output power into (from bottom to top at 2kHz) 4 ohms, 8 ohms, and 2 ohms (matched impedance taps).

Table 1 McIntosh MC2000 Clipping(1% THD+noise at 1kHz)

Both Channels DrivenOne Channel Driven W (dBW)W (dBW) Load
ohms (L) (R) (L) 8…

JMlab Chorus 706 loudspeaker

The most exciting development in audio today isn't multichannel surround, single-ended triodes, or $10,000 phono cartridges. It's "trickle down." I get buzzed when an audio designer known for cutting-edge multikilobuck designs claims to have a product that can produce 80% of the sonic realism of his flagship design at 50% of the cost. I get even more excited when he does it again—that is, produces a product that produces 64% of his flagship's performance at 25% of the cost. Designers who have successfully trickled-down their flagship technologies abound in all quarters of audiophilia, from…

JMlab Chorus 706 loudspeaker Page 2

The lower high frequencies, were somewhat sweetened; this added a slightly honeyed quality to instruments with significant high-frequency content. Louis Armstrong's trumpet had the requisite bite but sounded a bit more silky than I'd been used to hearing. Kevin Barry's Fender Stratocaster on the Mighty Sam disc seemed a bit more polite, as if Barry had swapped his Fender amp for a Mesa Boogie and hit the Fat switch. The extreme high frequencies also seemed a bit rolled-off, but not unnaturally so. The latter effect was akin to moving from a live hall (Avery Fisher or post-1980s-renovation…

JMlab Chorus 706 loudspeaker Specifications

Sidebar 1: Specifications

Description: Two-way bass-reflex bookshelf loudspeaker. Drive-units: 1" inverted-dome titanium tweeter with ¾" coil, 6½" Polyglas-cone woofer. Crossover frequency: 2.4kHz. Frequency response: 57Hz-22kHz, ±3dB. Sensitivity: 89.5dB/W/m. Impedance: 8 ohms nominal, 4 ohms minimum.
Dimensions: 14" (360mm) H by 7.75" (200mm) W by 10.13" (260mm) D. Weight: 13.6 lbs (6.2kg).
Finishes: Black, cherry, calvados.
Serial numbers of units reviewed: 10R004767 & 8.
Price: $450/pair. Approximate number of dealers: 60.
Manufacturer: Focal JMlab, 15 rue Jean…

JMlab Chorus 706 loudspeaker Associated Equipment

Sidebar 2: Associated Equipment

Analog source: VPI TNT IV turntable, Immedia RPM tonearm, Koetsu Urushi cartridge; Rega Planar 3 turntable, Syrinx PU-3 tonearm, Clearaudio Aurum Beta S cartridge.
Digital source: California Audio Labs Icon Mk.II Power Boss, Creek CD53 Mk.II CD players.
Preamplification: Vendetta Research SCP-2D phono stage, Audible Illusions Modulus L1 line stage.
Power amplifier: Audio Research VT100 Mk.II.
Integrated amplifiers: Creek 5350SE, JoLida JD-101A.
Cables: Interconnect: MIT MI-350 CVTwin Terminator, MIT MI-330SG, MIT Terminator 2. Speaker:…

JMlab Chorus 706 loudspeaker Measurements

Sidebar 3: Measurements

The JMlab Chorus 706 is specified as having a highish 89.5dB sensitivity; my measured figure was somewhat lower, at around 87dB, which is average. The speaker's impedance (fig.1) drops below 6 ohms only briefly in the lower midrange and the midbass, and while the electrical phase angle does approach ±45 degrees, this never coincides with a low magnitude. As a result, the 706 will be relatively easy to drive.

The blip at 200Hz in both of the traces in fig.1 suggests the presence of some kind of cabinet resonance at that frequency. There is a strong mode at…

Overcooked Floyd

The song ended. My friend gestured to me to remove the wads of Kleenex I had stuffed in my ears.

"This sucks. Can we leave?"

"I was going to ask you the same question. Why do they do that?"

I was in Austin's Continental Club, catching one of the many bands that were performing at this year's South By SouthWest music-biz conference. (Robert Baird reports from SXSW on p.154.) The Weary Boys were playing that most basic of American musics, bluegrass, on mainly acoustic instruments: guitars (one electric), fiddle, and double-bass. Yet the sound of those instruments via the…

Listening #13

When some people record music, they make an effort to record the ambient sound of the hall or other performing space along with it. On the other side of the coin, some engineers work to capture only the sounds of the performers, so the recordings they make sound comparatively dry. And, of course, there are engineers who don't make an effort one way or the other, and whose work contains whatever hall sound does or does not come their way by accident.

The libraries and private collections of the world are filled with great recordings—masterpieces, in some instances—that were made in all the…

Listening #13 Page 2

...but remember!
Leonard Bernstein made some artistically brilliant recordings during the years when his label, Columbia Masterworks, opted for a house sound that today's audiophiles abhor: a little bit edgy and a little bit colorless, with brass instruments that sound too lean, instrumental images that often exhibit "unrealistic" (hoo, boy—don't get me started on that one) scale and perspective, and a shocking dearth of both stage depth and audible subway trains.

A lot of people choose not to listen to Bernstein's recordings, and that's their right. But to ignore his music merely…

Acoustic Research AR-1 loudspeaker

Experienced reviewers know that shows are the wrong environments for critical audiophile listening. Convention centers—especially the one at Las Vegas—are huge, cavernous airplane hangers, not the intimate listening rooms reviewers thrive in. Extraneous sounds from subwoofer blasts and the constantly milling crowds leak in to sully the music. Booths set up by manufacturers on the show floor have very thin, flexible walls, and no bass treatment.

So the floor of the Las Vegas Convention center was the last place I expected to hear a pair of loudspeakers produce three-dimensional imaging.…