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Dominating the front panel are an LED bargraph, which displays output power calculated from voltage, and a digital power meter that shows actual output power. I did as Inokuma suggested and watched the output power at my normal listening levels. It rarely exceeded 62.5W, the power at which the amplifier switches from class-A to class-AB with a nominal 4 ohm load like the Wilson Alexia V.

Beneath the meters is a Standby/On button. When you turn the amplifier on, the outputs mute for about five seconds to allow the circuit time to stabilize. The power button is framed by a panel-…

Description: Solid state, class-A (into 8 ohms) mono power amplifier. Inputs: one each balanced (XLR), single-ended (RCA). Output: 2 pairs loudspeaker binding posts per channel, RCA and XLR outputs for bridging and biamping. Rated output power: 125W into 8 ohms, 250W into 4 ohms, 500W into 2 ohms, 1000W into 1 ohm (all 21dBW). Frequency response: 20Hz–20kHz (+0, –0.2dB) at full rated power; 0.5Hz–160kHz (+0, –3dB) at 1W. Input impedance: 40k ohms balanced; 20k ohms single-ended. Signal/noise ratio (A-weighted, input shorted): 130dB with Gain switch set to MAX,…

Digital sources: dCS Vivaldi Apex DAC, Vivaldi Upsampler Plus, Vivaldi Master Clock; Innuos Statement Next-Gen Music Server; Small Green Computer Sonore Deluxe opticalModule; Uptone Audio EtherRegen with SOtM sCLK-OCX10 Master Clock and sPS-500 power supply; Nordost QSource linear power supplies (2); HDPlex 300 linear power supply; Synology 5-bay 1019+ NAS powered by Ferrum Hypsos linear/switching hybrid power supply; Linksys mesh router and Arris modem; 2017 Apple iPad Pro, 2017 MacBook Pro laptop with 2.8GHz Intel i7, SSD, 16GB RAM.
Preamplifier: Dan…

I performed a complete set of measurements on one of the Accuphase A-300s (serial number L2Y188) in its Normal mode with my Audio Precision SYS2722 system. I preconditioned the A-300 by following the CEA's recommendation of running it at one-eighth the specified power into 8 ohms for 30 minutes. At the end of that time, the temperature of the top panel was 97.6°F (36.4°C) and that of the side-mounted heatsinks 120.4°F (49.1°C).

As auditioned by JVS, the balanced input was wired with pin 2 negative, the opposite of the AES standard. (A rear-panel switch…

I had my reasons—especially price. The prices of those earlier Estelons were a poor fit for my budget. I was also troubled by the fact that, despite rhetoric about driver and component choice, advanced cabinet materials and construction, and fastidious engineering, Estelon has been stingy with details and specifications—not a complete disqualifier but rather a missed opportunity to…

Hankering for a recording with a greater sense of space and place, I moved to another recording by Les Siècles, one that has become a favorite of mine, Fauré's Requiem Op.48, which adds the vocal group Ensemble Aedes to the mix, both ensembles conducted by Mathieu Romano (24/96 FLAC, Aparté AP201). This piece was recorded in Abbaye de Lessay, in Manche, which offers a warm acoustic without loss of detail. From the first, defining pedal, everything was sweet and clear, and the AURAs delivered the voices and instruments distinct from the enveloping ambience. However, I heard less of the…

Description: Three-way, four-driver floorstanding loudspeaker in a sealed, "thermoformed composite" enclosure. Drive units: 1" (26mm) Scan-Speak textile-dome "Illuminator" tweeter, two 5" (130mm) "Satori" Egyptian Papyrus-cone midwoofers, one 10" (250mm) "Faital" hard-pressed paper-cone woofer. Kubala-Sosna internal wiring. Frequency range: 35Hz–25kHz. Impedance: 4 ohms (minimum 2 ohms at 58Hz). Sensitivity: 90dB/2.83V/1m. Minimum amplifier power: 30W. Recommended room size: 160–645ft2.
Dimensions: 53.7" (1366mm) H × 15.1" (384mm) W × 14.4" (367mm) D…

Digital sources: Oppo Digital UDP-103 universal disc player, Custom Intel/Win11 music server running JRiver Media Center v30 and Roon, Merging Technologies Hapi MKII, exaSound s88 Mark II, and Okto DAC8 Pro D/A processors. QNAP TVS-873 NAS. Preamplifiers Coleman Audio 7.1SW for balanced DAC-to-amp switching.
Power amplifiers: Benchmark AHB2, NAD C 298.
Loudspeakers: KEF Blade 2 Meta, Revel Performa3 f206; two JL Audio e110 and 1 SVS SB-3000 subwoofers.
Cables: Digital cables: AudioQuest Coffee (USB). Analog interconnects: Benchmark Studio&…

I measured one of the Estelon Aura loudspeakers, serial number F35204B, in KR's apartment, using his NAD C 298 amplifier for the testing. I measured the Estelon Aura's impedance with Dayton Audio's DATS V2 system and used DRA Labs' MLSSA system with a calibrated DPA 4006 microphone to measure the speaker's behavior in the farfield and an Earthworks QTC-40 mike for the nearfield responses. Kal and I lifted the Aura on to a dolly for the measurements, but to minimize the effect of the first reflection from the ground, I measured the response and dispersion with the…