search

Simaudio Moon Rock monoblock power amplifier Measurements

Sidebar 3: Measurements

I preconditioned the kilowatt Simaudio Moon Rock by running it at 300W into 8 ohms for an hour. After 30 minutes the chassis was warm but the heatsinks were too hot to touch, suggesting that they are smaller than required to pass the FTC heat test. However, this will be of little consequence in actual use. More important, the distortion level at this power output had hardly increased with the rise in temperature. Starting at 0.0028% with the amplifier cold, the distortion still measured only 0.0029% at the end of the preconditioning period.

The voltage…

Meadowlark HotRod Shearwater loudspeaker

Though each link in the audio chain is significant in its own way, we seem to spend more time agonizing over the choice and setup of loudspeakers than any other component. Floorstanding or stand-mounted? Full-range frequency extension or minimonitor coherence? Multiple-driver complexity or two-way simplicity? Pleasurable and forgiving or resolved and revealing? And even when money is no object, how much speaker do you really want...or need? It might sound splendid in the shop, but how will it couple with your room? How will it integrate with your other gear? Is it easy to set up and drive or…

Meadowlark HotRod Shearwater loudspeaker Page 2

Swooning in a Sepia Glow
For the Shearwaters' initial break-in period, Meadowlark suggests at least 300 hours! Over time, I observed how the tweeter's performance grew sweeter and more open, while the bass driver's focus grew firmer and more dynamic. Thereafter, week by week, they had a greater sense of ease, balance, and focus, which translated into improved midrange lucidity with a commensurate increase in depth and detail.

To optimize the sweet spot, I needed to be fastidious about setup. This has a lot to do with the integration of the drivers in a time-coherent, first-order…

Meadowlark HotRod Shearwater loudspeaker Page 3

Warmly ingratiating? Yes, there was indeed a certain touch of bloom in the lower-midrange-to-midrange transition between middle C and A-440 on the piano. Were the Hot Rod Shearwaters "precise" enough for members of the crowd who eschew personality in speakers? Perhaps not, but I experienced the Shearwaters' sonic signature as neither colorations nor tweaky emphases, but as a welcome touch of character—and believe you me, their midrange was the glory of my analog front-end. On a three-LP set of Pablo Casals' famous 1936-39 recordings of J.S. Bach's Six Suites for Cello Solo (Angel CB-3786),…

Meadowlark HotRod Shearwater loudspeaker Page 4

Goodness In, Goodness Out
In the Meadowlark Hot Rod Shearwater, designer Pat McGinty's determination to maintain the absolute integrity of the musical waveform has resulted in a presentation that is accurate without being analytical: spectrally balanced, dimensionally full, and a dream to drive. Talk about cruise control—it displayed terrific speed and bass extension with a modestly powered solid-state integrated amp like the Simaudio i-5, and a gloriously deep, detailed midrange with a tubed juggernaut such as the VTL MB-450. Stacked up against the best two-way floorstanding designs I'…

Meadowlark HotRod Shearwater loudspeaker Specifications

Sidebar 1: Specifications

Description: Two-way floorstanding loudspeaker with transmission-line woofer loading. Drive-units: 1" ScanSpeak D2905/95000 fabric-dome tweeter, 7" ScanSpeak 18W8545 carbon-graphite long-throw woofer. Crossover: 2.7kHz, first-order electrical with damped resonance shunt. Frequency response: 35Hz-25kHz, -3dB. Sensitivity: 88dB/2.83V/m room, white noise. Nominal impedance: 8 ohms.
Dimensions: 40" H by 9" W by 11" D. Shipping weight: 43 lbs each.
Finishes: Cherry, Straight Grain Ash, Classic Mahogany, Rosewood, Ebony. Birch, Maple, Sapele, Walnut, add $300;…

Meadowlark HotRod Shearwater loudspeaker Associated Equipment

Sidebar 2: Associated Equipment

Analog source: Rega Planar 25 turntable with RB600 tonearm and Grado Statement Master cartridge; Marantz PMD430 cassette player/recorder.
Digital source: Sony SCD-777ES SACD/CD player, California Audio Labs CL-20 DVD/CD player and Alpha 24-bit/96kHz tubed DAC, Musical Fidelity A3 CD player.
Preamplification: Musical Fidelity Nu-Vista, Blue Circle Galatea, VTL 5.5, Rogue Audio Magnum Ninety-Nine preamplifiers; Blue Circle BC22 phono stage.
Power amplifiers: Musical Fidelity Nu-Vista 300, Mesa Baron, VTL MB-450, Rogue Audio Magnum M120.
…

Meadowlark HotRod Shearwater loudspeaker Measurements

Sidebar 3: Measurements

The Meadowlark Shearwater is of below-average voltage sensitivity, at an estimated 84.5dB(B)/2.83V/m. However, its impedance plot (fig.1) suggests that it's an easy load for the partnering amplifier to drive, the magnitude dropping below 8 ohms only in the midbass and lower midrange. A spike in the magnitude trace around 150Hz, coupled with a glitch in the electrical phase trace at the same frequency, suggests the presence of a major cabinet resonance. There is also a much smaller glitch just below 300Hz, and a cumulative spectral-decay plot derived from the…

Meadowlark HotRod Shearwater loudspeaker Measurements part 2

In the vertical plane (fig.6), a presence-region suckout that develops immediately above the tweeter axis might balance the off-axis flare. On the other hand, sit lower than the tweeter and more presence-region energy becomes apparent, which will exaggerate the subjective consequences of the flare in the dispersion pattern. That Chip felt the speaker was, if anything, somewhat on the laidback side suggests that it is the lack of off-axis energy below and around 3kHz in both planes that dominates the Shearwater's perceived balance.

Fig.6 Meadowlark Shearwater, vertical response…

Wavelength Audio Gemini monoblock power amplifier

"I'm a fan of tubes—I don't like designing with them, but I do like listening to them."—Paul McGowan, Stereophile interview, May 2000

"Over the years I have received numerous compliments on my work, but some of the nicest have been from hard-core tube lovers who have told me that my amps 'sound a lot like tubes!' or words to that effect. I take that as high praise, indeed."—Steve McCormack, "Manufacturer's Comment" on review of McCormack DNA-125, Stereophile, December 2000

One audio designer who does like designing with tubes, and whose amplifiers definitely sound like…