Sidebar 5: Measurements
A full set of measurements of the Sumo Andromeda III was made using its unbalanced inputs. Most readings were repeated with the balanced inputs and these are noted below where appropriate.
Following the 1/3-power, one-hour preconditioning test, the Andromeda III's heatsinks were quite hot, as was the top of the case itself. The input impedance measured 49.6k ohms (95.8k ohms, balanced). The output impedance was 0.033 ohms or below at 1kHz and 20Hz, increasing to a maximum of 0.39 ohms at 20kHz. The frequency response of the Sumo should be virtually…
Sidebar 6: Specifications
Sumo Andromeda: Solid-state, class-AB stereo power amplifier. Rated power: 200Wpc into 8 ohms (23dBW) at less than 0.05% THD, 375Wpc into 4 ohms (22.8dBW) at less than 0.1% THD.
Dimensions: 19" Wby7" D by 83,4 " H. Weight: 35 lbs.
Price: $899.
Manufacturer: AllAmerican Audio, Inc., Westlake Village, CA, 91362.
Sumo Andromeda II: Solid-state stereo power amplifier. Rated power output: 240Wpc into 8 ohms (23.8dBW) with less than 0.05% THD, 400Wpc into 4 ohms (23dBW) with less than 0.1% THD, from 20Hz–20kHz. Intermodulation distortion (IMD): 0.…
I like reviewing loudspeakers. The more you become familiar with the art, the greater the sense of anticipation as you open up a pair of cartons. A visual inspection of the speaker always reveals a challenging mixture of the familiar and the new. The size of the cabinet is always the first clue—has sensitivity been a design priority or was low-frequency extension uppermost in the designer's thoughts? You espy a known drive-unit—has this tweeter's propensity for upper-presence sizzle been tamed? You find a reflex port on the rear panel—has the temptation to go for a "commercial," under-damped…
All things being equal, the larger the cabinet, the lower in frequency and potentially the more audible the resonances of its panels. Though a large cabinet undoubtedly confers a higher sensitivity and deeper bass extension, these are often obtained at the expense of greater levels of midrange coloration. With a speaker like the Concept 200, extra effort has to be taken in the construction of the enclosure. The 200 features what is called by its designers "Impact-Braced" technology. This high-tech nomenclature describes a bracing system whereby the side panels have additional grooved panels…
Sidebar 1: Specifications
Description: two-way, reflex-loaded, floor-standing loudspeaker. Drive-units: 19mm (0.75") hyperbolic soft-dome tweeter, two 165mm (6.5") trilaminate-filled polypropylene-cone woofers. Crossover frequency: 2kHz. Frequency response: 30Hz–23kHz ±2dB. Sensitivity: 87dB/W/m. Nominal impedance: 8 ohms. Amplifier requirements: 50–150W (300W peak).
Dimensions: 41 1/8" H by 9 7/8" W by 15½" D. Weight: 66 lbs each.
Price: $1000/pair (1988); no longer available (2010). Approximate number of dealers: 60 (1988).
Manufacturer: Image Loudspeakers, Markham, Ontario…
Sidebar 2: Review System
The test procedure followed that established for my previous loudspeaker reviews: each pair was used both with a Krell KRS2/KSA-50 combination and the Linn LK1/LK2 remote-control amplification system. Source components consisted of a Marantz CD94 CD player used via its optical digital output to feed a Marantz CDA94 outboard DAC unit, and a Linn Sondek/Ittok/Troika combination sitting on a Sound Organization table. Interconnect for the Krell system was Monster M1000, with Monster M1 speaker cable. The Linn system was used with Linn interconnect and speaker cable.…
Sidebar 3: Measurements
The Image 200's frequency response was measured in the listening window—spatially averaged to minimize room standing-wave problems—using a 1/3-octave warble-tone generator; the nearfield low-frequency response of each speaker was also measured with a sinewave sweep to get an idea of the true bass extension relative to the level at 100Hz. The change of impedance with frequency and the voltage sensitivity (using 1/3-octave pink noise centered on 1kHz) were also measured.
Fig.1, the plot of impedance with frequency, shows the Image 200 to be a reasonably…
The arrival of the Mark Levinson No.30 digital processor more than 2½ years ago marked a turning point in digital-audio reproduction. Although the No.30's $13,950 price tag put it out of reach of all but a few audiophiles, its stunning performance suggested that much more musical information was encoded on our CDs, waiting to be recovered by better digital processors. Further, it was inevitable that this level of performance would become less expensive over time. I was more excited by the No.30 than I've been over any other audio product. In fact, its musical performance was so spectacular…
Madrigal has taken a completely different approach to clock generation. The No.30.5 recovers the input signal and clock with a conventional Crystal CS8412 input receiver. But instead of sending that audio data and clock to the digital filter and the DACs, it's input to a First-In, First-Out (FIFO) RAM buffer. The buffer can accept data at a varying rate (caused by jitter or clock-frequency instability from the CD transport), but can output data with near-perfect precision. The output clock that ends up controlling when the DACs convert the digital samples to analog (the point where clock…
The extreme bottom end—always the No.30's Achilles' heel—was more extended and tighter through the No.30.5. Although the SFD-2 had more bottom-end punch, the No.30.5 was a huge improvement over the No.30.
A large part of why I liked the SFD-2 more than the No.30 was the SFD-2's cleaner treble. By comparison, the No.30 had a layer of grain over the treble, and a slightly metallic quality. There was also a certain "coldness" to the No.30's sound that was largely the result of the treble grain.
Fortunately, the No.30.5 has none of these characteristics. Its treble was much smoother…
