AudioQuest, 2621 White Road, Irvine, CA 92614. Tel: (949) 585-0111. Web: www.audioquest.com
Triode Wire Labs, PO Box 32. Massapequa Park, NY 11762. Tel: (516) 659-6748. Web: www.triodewirelabs.com
search
It was almost seven years ago that Nelson Pass, whose talks and exhibits I'd covered at many a Bay Area Burning Amp DIY event and audio show, surprised me with a loan of two Pass Laboratories' XA 160.5 class-A monoblock amplifiers. Ten months later, after I'd commented that my system had challenged the XA 160.5s in the bass department, he sent me a pair of XA200.5 monos. I connected those bigger babies to Wilson Audio Sophia 3 loudspeakers and some now-discontinued digital components with Nordost Odin 1 interconnects and speaker cables. Then came my way, toward the end of 2016, the XA200.8…
Just as many inspired musicians invest their sound with a soulful glow that can grow in brilliance, the XA200.8s seemed to illuminate music from within in a way that complemented that artistic brilliance. In contrast with some tube amplification of my experience, the inner glow I heard with the XA200.8s sounded like something that arose organically from within the music. At the beginning of Mahler's Symphony 2, in the recording by Iván Fischer and the Budapest Festival Orchestra (SACD/CD, Channel Classics CCS SA 23506), the impact of the ominous march of cellos and double basses, the cries…
Sidebar 1: Specifications
Description: Solid-state, monoblock power amplifier. Inputs: 1 balanced (XLR), 1 single-ended (RCA). Power output: 200W into 8 ohms, 400W into 4 ohms (both 23dBW). Frequency range: 1.5Hz–100kHz. Voltage gain: 26dB. Input impedance: 50k ohms single-ended, 100k ohms balanced. THD (1kHz, full power): 1%. Damping factor: 200. Output noise: 200µV. Input CMRR (common-mode rejection ratio): 60dB. DC offset: 0.05V. Current draw at idle: 6.3 amps. Power consumption: 760W. Temperature: 53°C.
Dimensions: 19" (480mm) W by 11" (280mm) H by 27.5" (700mm) D. Weight: 157 lb…
Sidebar 2: Associated Equipment
Digital Sources: dCS Paganini SACD/CD transport, Scarlatti clock, Rossini & Vivaldi DACs, Network Bridge; Intel NUC7i7BNH computer with 8GB RAM, 128GB SSD, running Roon; Linksys router with two TP-Link gigabit Ethernet media converters & multimode duplex fiber-optic cable; external hard drives, USB sticks, Apple iPad Pro.
Power Amplifiers: Dan D'Agostino Master Audio Systems Progression Mono monoblocks.
Loudspeakers: Wilson Audio Specialties Alexia and Alexia 2.
Cables: Digital: AudioQuest Diamond (Ethernet), Nordost Odin 1 & Odin 2…
Sidebar 3: Measurements
Before performing any measurements, I ran one Pass Labs XA200.8 (serial no. 29556) for an hour at one-third its measured maximum power into 8 ohms—thermally, the worst case for an amplifier with a class-AB output stage but not for a true class-A amplifier, which runs at its hottest with no signal. By the end of the hour, the top panel was warm, at 99.4°F (37.4°C), and the side-mounted heatsinks were hotter, at 118.1°F (47.8°C). Although Pass Labs specifies the XA200.8 operating in class-A, I suspect that even with its massive heatsinking, the amplifier doesn't…
The Emitter II Exclusive integrated amplifier, from German manufacturer ASR Audio, challenged my idea of what I could expect from a solid-state amplifier and my thoughts of what might be the best amp for driving a pair of Quad ESL loudspeakers—revelations that were more or less inseparable. After hearing my friend and former neighbor Neal Newman drive his own ESLs with a ca 1975 sample of the Quad 303—a solid-state amplifier rated at 45Wpc into 8 ohms—and after my experiences, in 2016, driving my ESLs with a borrowed sample of the 18Wpc, solid-state Naim Nait 2, I began to think that Quad-…
Listening
We began by listening to the DeVore O/93s. I was immediately struck by an increase in top-end sparkle and air, compared to when the speakers were driven by my Shindo Laboratory preamp and power amp. Perhaps for that reason, the ASR made my system sound bigger with some recordings—this was not consistent across all of the listening I did with the ASR-DeVore combination, but never did that combination sound smaller than when I used the Shindos. Also with the DeVores, the ASR didn't squeeze out the same degree of timbral-color saturation as the Shindos, from any recording. But…
We began by listening to the DeVore O/93s. I was immediately struck by an increase in top-end sparkle and air, compared to when the speakers were driven by my Shindo Laboratory preamp and power amp. Perhaps for that reason, the ASR made my system sound bigger with some recordings—this was not consistent across all of the listening I did with the ASR-DeVore combination, but never did that combination sound smaller than when I used the Shindos. Also with the DeVores, the ASR didn't squeeze out the same degree of timbral-color saturation as the Shindos, from any recording. But…
Not everyone needs a power amplifier that can deliver 888W RMS into 8 ohms or 1776W into 4 ohms. You could say that no one needs one of these—or two, if you want to listen in stereo. Most household AC systems can't even provide enough current to deliver all that power. But Simaudio does build Moon 888 monoblocks, and people do buy them, whether or not they need an amp that weighs about 250 lb each and costs $118,888/pair.
But forget about need. Would you want a pair of these massively heavy amps? People into tubed gear might not, but if price was not a consideration and if you had the…
Although the class-AB Moon 888 consumes a relatively low 50W at idle, its prodigious power output and linear power supply mean that it won't be the most energy-efficient device in your home. It has two standby modes: Low Power and Default. Though Low Power powers down all but the logic circuit, Simaudio recommends using Default mode, in which the gain stages remain active. This maintains the 888's ideal operating temperature: it's always ready to play, without warmup. Whether your concern is environmental or financial—the latter is unlikely, if you're dropping $118,888—you're covered.
…