Digital Sources: dCS Paganini SACD/CD transport & Scarlatti clock & Vivaldi DAC & Network Bridge; Linksys router with two TP-Link gigabit Ethernet media converters, multimode duplex fiber-optic cable; external hard drives, USB sticks, iPad Pro.
Preamplifier: Audio Research REF 6.
Power Amplifiers: Dan D'Agostino Master Systems Progression monoblocks, Pass Laboratories XA200.8 monoblocks.
Loudspeakers: Wilson Audio Specialties Alexia 2.
Cables: Digital: AudioQuest Diamond, Wireworld Platinum Starlight Cat8 (Ethernet); Nordost…
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This Audio Research amplifier presented a measuring challenge. It has balanced and single-ended inputs, two different modes of operation, and three output-transformer taps. It is therefore 12 different amplifiers. I performed full sets of tests using its balanced input in both Triode and Ultralinear modes from the 4 ohm and 8 ohm output taps, then repeated some of the tests using its single-ended input and the 16 ohm tap. After I installed the tubes, I used the Tube Monitor button on the front panel to make sure all was well with the KT150 output tubes—all four…
Description: Solid-state stereo power amplifier. Inputs: 1 pair unbalanced (RCA), 1 pair balanced (XLR), 1 pair Direct (XLR), 12V trigger (3.5mm jack), control (USB). Outputs: 2 pairs speaker binding posts. Power output: 500Wpc into 8 ohms (27dBW), 1000Wpc into 4 ohms (27dBW), 1600Wpc into 2 ohms (26dBW). Frequency response: 10Hz–100kHz, +1/–0.5dB. Voltage gain: 26dB (balanced & RCA), 14dB (Direct). THD+N: <0.05% at 1kHz, rated power. Noise: <70µV (500kHz bandwidth). Signal/noise: 116dB ref. 250W. Input impedance: 100k ohms unbalanced, 200k ohms…
Analog Source: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B cartridge.
Digital Sources: Roon Nucleus+ music server; Ayre Acoustics C-5xeMP universal player; PS Audio PerfectWave DirectStream D/A converter; Ayre Acoustics QA-9 USB A/D converter.
Preamplification: Channel D Seta L phono preamplifier.
Power Amplifiers: Bricasti Design M15, Lamm Industries M1.2 Reference (monoblocks).
Loudspeakers: Dynaudio Special Forty, Tidal Audio Akira, Wilson Audio Specialties Alexia Series 2.
Cables: Digital:…
I measured the Constellation Performance Centaur II 500 using my Audio Precision SYS2722 system (see the January 2008 "As We See It"). Before I test an amplifier, I precondition it with both channels driving a 1kHz tone at one-third power into 8 ohms for an hour. At the end of that time, the Constellation's enclosure was hottest toward the rear of the top panel, at 101.3°F (38.5°C).
The voltage gain at 1kHz from the speaker terminals into 8 ohms measured 25.9dB for both balanced and unbalanced signals, and 12dB for the Direct input. All sets of inputs…
Jeffrey put on an album by the late R.L. Burnside, a country-blues singer and guitarist. A repeated acoustic-guitar phrase appeared from the direction of the speakers—an up-tempo, rhythmically driving sound that seemed physically whole and real,…