Although the Rogue 66LSR was tested using its "CD" inputs, all of its inputs appear identical, including the one marked Phono. The unity-gain setting of the volume control was 3:00, and the gain with the volume control at its maximum measured very much lower than specified: 9.1dB rather than 23dB. In addition, the second pair of outputs was inoperative in either passive or active mode. As all the operating voltages appeared to be correct, no fuses were blown, and there was no sign of "cooked" components, I assumed that the preamp's main signal path was operating…
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The Rogue preamplifier gave the lowest THD+noise readings when its input and output floated above ground, which suggests something peculiar in its internal grounding. Much to my surprise, the 66LSR gave lower distortion into 10k ohms than into 100k ohms. This can be seen in fig.4, which plots the THD+N percentage against the output voltage into the two loads. The lower trace was taken into 10k ohms, and reveals a sensible gain architecture: the preamp offers the lowest distortion, 0.07%, at around 2V output, which is near the level at which the partnering amplifier will clip. Below that…
When I learned that Madrigal Audio Labs was marketing their first integrated amplifier, the Mark Levinson No.383, I felt this was a big change for the Connecticut company. Mark Levinson literally started the high-end marketing revolution back in the early 1970s by manufacturing cost-no-object separate amplifiers and preamplifiers. The purist designs had one overriding rule: employ the simplest circuit path possible. Each amplifier or preamplifier used only individual circuit-board components (no integrated circuits) and had a minimal number of controls, eschewing elaborate switches and tone…
Ergonomic Heaven
That user-friendliness begins with the No.383's size and weight. At 65 lbs, this baby is the lightest and smallest ML amplifier. The 112-lb No.334 ($5900), the 155-lb, 250Wpc No.335 ($7900), and the 165-lb, 350Wpc No.336 ($9500) are so massive that they require two people—both wearing Madrigal's white-ribbed protective gloves, of course—to safely unpack them.
That user-friendliness begins with the No.383's size and weight. At 65 lbs, this baby is the lightest and smallest ML amplifier. The 112-lb No.334 ($5900), the 155-lb, 250Wpc No.335 ($7900), and the 165-lb, 350Wpc No.336 ($9500) are so massive that they require two people—both wearing Madrigal's white-ribbed protective gloves, of course—to safely unpack them.
Stacking the No.383 atop a Mark Levinson No.334 made this point convincingly. The No.383 shares most of the No.334's physical dimensions, including its width and depth. It, too, has the rounded heatsink edges…
Circuitry and Construction
The No.383's back panel features five analog input pairs, for use with sources single-ended (three pairs of Madrigal-designed RCA inputs) or balanced (two pairs of Swiss-made XLR inputs). The No.383's rear handles protect the interconnect cables if the unit is upended onto its rear panel. All the sockets mount directly to the printed-circuit board (PCB), and inputs are independently buffered. Unselected inputs have their ground connections lifted, eliminating a path by which noise might enter the chassis. All single-ended signals are converted to balanced at…
The No.383's back panel features five analog input pairs, for use with sources single-ended (three pairs of Madrigal-designed RCA inputs) or balanced (two pairs of Swiss-made XLR inputs). The No.383's rear handles protect the interconnect cables if the unit is upended onto its rear panel. All the sockets mount directly to the printed-circuit board (PCB), and inputs are independently buffered. Unselected inputs have their ground connections lifted, eliminating a path by which noise might enter the chassis. All single-ended signals are converted to balanced at…
Listening
Most listening was done in the nearfield of my current reference loudspeakers, the Revel Salons. These sat on a circular area rug, 63" from the rear wall and 36" from the sidewalls. Imaging and soundstaging were optimized when speakers and listening chair described an 8' equilateral triangle, measured from the tweeter centers.
Most listening was done in the nearfield of my current reference loudspeakers, the Revel Salons. These sat on a circular area rug, 63" from the rear wall and 36" from the sidewalls. Imaging and soundstaging were optimized when speakers and listening chair described an 8' equilateral triangle, measured from the tweeter centers.
The good news is that the No.383 played with clarity, transparency, liquid mids and highs, and an ability to render dynamic contrasts second only to that of the Mark Levinson No.334. Whether driving the Dynaudio Contour 3.0s, Quad ESL-63s, B&W…
Sidebar 1: Specifications
Description: Solid-state integrated stereo amplifier.
Preamplifier section: Line-level inputs: two pairs balanced (XLR), three pairs single-ended (RCA, optional). Outputs: one pair record outputs (RCA), one IEC AC mains receptacle, one ground terminal. Controller connections: three 3.5mm mini-jacks (IR input, DC trigger out/in), one Mark Levinson Link communications connector, one 6-pin RJ-11 RS-232 port, two 8-pin RJ-45 control ports (PHASTLink-compatible). Voltage gain: 0, 6, 12, or 18dB in line stage (26.9dB in amplifier stage). Volume control range: 72.…
Sidebar 2: Associated Equipment
Analog source: Linn Sondek LP12/Lingo turntable with Ittok tonearm, Spectral moving-coil cartridge.
Digital source: Sony MZ-R90 MiniDisc player, Krell MD-1 CD transport, Denon DVD-3700 DVD player, Adcom GDA-700 D/A processor.
Tuners: Day-Sequerra FM Reference Classic, Rotel RH-10, Magnum Dynalab MD-102 with 205 Sleuth RF amplifier.
Preamplification: Krell KBL, Mark Levinson ML-7A with L-2 phono section, Duntech MX-10 moving-coil preamplifier.
Power amplifiers: Mark Levinson No.334, Bryston 7B-ST monoblocks.
Loudspeakers: Dynaudio Contour 3.0…
Sidebar 3: Measurements
A one-hour preconditioning warmup at one-third full power exerts maximal thermal stress on an amplifier with a class-B output stage, and after that hour the No.383 was indeed warm to the touch—but not so hot that I couldn't keep my hand on its heatsink.
The amplifier didn't invert absolute polarity. (The XLR inputs appear to be wired with pin 2 hot.) The input impedance was 19k ohms balanced and 10k ohms unbalanced at 1kHz, both lower than the specified 100k ohms. The tape output source impedance was a low 50 ohms. With the line-stage gain set to "6dB,"…
Small-signal THD was very low over most of the audioband, rising slightly in the top audio octave and into lower impedances (fig.4). The actual harmonic content was buried in noise at reasonable power levels; fig.5 shows that it is fundamentally third harmonic. At high powers (fig.6), the third harmonic rose to a still low 0.05% (-66dB) and was joined by the fifth at 0.01% (-80dB). Intermodulation levels were also respectably low, even just below visible clipping into a 4 ohm load (fig.7).
Fig.4 Mark Levinson No.383, THD+noise (%) vs frequency at (from top to bottom at 4kHz): 4W…