My musical history began in the 1980s at a 10W radio station attached to the library of my high school in…
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For over three decades, I have felt compelled to turn people on to music. Throughout my career as a DJ, all of my endeavors have been linked by the desire to spread the joy of listening to records, in the hope that people would feel something like the emotional resonance I feel. My Classic Album Sundays adventure—see www.stereophile.com/content/classic-album-sundays-bellwether— was born from this lifelong dedication to musical curating, and propelled by a eureka hi-fi moment.
The only thing better than a review that writes itself is a product with a compelling story. Although the latter asks a little more of us here, it's usually the more enduring pleasure.
So it goes with the new AX-5 amplifier ($9950) from Ayre Acoustics, in which designer Charles Hansen has both revived an overlooked technology from a half-century ago and brought to market a more affordable embodiment of one of his own most well-received products. All this comes in a package that requires no more room than the average electric typewriter, and that takes the place of everything you might…
One could also rely on the included remote handset: a big, hefty, confidence-inspiring piece of metal that I came to enjoy more than most such devices. I especially enjoyed using its illumination button—the only soft-touch button on the handset that's set aside from all the others, allowing the user to more easily find it in the dark—which back-lights, for approximately eight seconds, all of the handset's soft-touch pictographs, most of which make sense.
Two miscellaneous setup observations:
With the AX-5, Ayre endures in using Cardas's proprietary single-knob speaker-terminal…
Sidebar 1: Specifications
Description: Solid-state integrated amplifier. Line-level inputs: 4 balanced (XLR), 2 single-ended (RCA). Input impedance: 2 megohms balanced, 1 megohm single-ended. Maximum input level: 16V RMS balanced, 8V RMS single-ended. Maximum gain: 32dB. Frequency response: DC–250kHz. Output power: 125Wpc into 8 ohms (21dBW), 250Wpc into 4 ohms (21dBW).
Dimensions: 17.25" (440mm) W by 4.875" (125mm) H by 18.75" (480mm) D. Weight: 46 lbs (20.9kg).
Serial number of unit reviewed: 22AO124C.
Price: $9950. Approximate number of dealers: 40.
Manufacturer: Ayre…
Sidebar 2: Associated Equipment
Analog Sources: Garrard 301, Thorens TD 124 turntables; EMT 997, Ikeda IT-407 tonearms; EMT TSD 15 70th Anniversary pickup head; Miyabi 47, Miyajima Premium BE mono cartridges.
Digital Sources: Ayre Acoustics QB-9, Wavelength Proton USB DACs; Apple iMac G5 computer running Apple iTunes v.11.0, Decibel v.1.0.2 playback software; Sony SCD-777ES SACD/CD player.
Preamplification: Auditorium 23 Standard (SPU version), Hommage T2 step-up transformers; Sutherland Engineering Insight phono preamplifier; Shindo Masseto preamplifier.
Power Amplifiers:…
Sidebar 3: Measurements
I measured the Ayre AX-5 using Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com). Before performing any measurements on an amplifier, I run it for an hour with both channels driven at one-third its rated power into 8 ohms; with an amplifier having a class-A/B output stage, this maximally thermally stresses the output devices. At the start of the 60 minutes, the AX-5's THD+noise measured 0.045%; at the end, it had dropped to 0.031% and the internal heatsinks were hot, at 122.9°F (50.…
Apple's iPod came of age in the fall of 2003, when, with the release of iTunes 4.5, the player was no longer restricted to lossy compressed MP3 or AAC files. Instead, it could play uncompressed or losslessly compressed files with true "CD quality"; users no longer had to compromise sound quality to benefit from the iPod's convenience.
Ten years later, while the current top-model iPod features a 160GB hard drive, it still can play only files with sample rates of 48kHz and below and a maximum bit depth of 16. Those of us with a growing library of high-resolution files are therefore…
My Sennheiser HD650 'phones have a nominal impedance of 220 ohms, which might suggest that they would be a much better match for the AK100. However, the downside of this high load impedance is reduced sensitivity: the AK100 couldn't drive the Sennheisers to anything like a loud enough level. With an impedance that varies between 70 and 95 ohms, the closed-back Sony MDR-7506 should work well with the AK100. Certainly, the AK100 had no problem driving the MDR-7506s to high levels.
Listening
I used the AK100 for six weeks of listening, mostly on the move but also for headphone…
Sidebar 1: Specifications
Description: Battery-powered portable media player & D/A processor with 2.4" touchscreen (320x240 pixels), 32GB internal memory, and two Micro-SD card slots. Digital inputs: 1 S/PDIF TosLink on 3.5mm jack. Digital output: S/PDIF TosLink on 3.5mm jack. Analog output: 1 pair unbalanced on 3.5mm stereo jack. Resolutions and sample rates supported: 16-bit, 44.1, 48, 88.2, 96, 176.4, 192kHz (internal); 16/24-bit, 44.1, 48, 88.2, 96kHz (TosLink). File formats supported: WAV, FLAC, Ogg, APE, AAC, ALAC, AIFF, MP3. Frequency response: 20Hz–20kHz, ±0.02dB. Channel…
Sidebar 2: Associated Equipment
Digital Sources: Apple iPod Classic 160GB, Ayre Acoustics C-5xeMP universal player; Apple 2.7GHz i7 Mac mini running OS10.7, iTunes 10, Pure Music 1.86; Schiit Bifrost, Arcam FMJ D33 D/A converters.
Preamplification: Pass Labs XP-30 line preamplifier.
Headphone amplifier: Ray Samuels Audio Emmeline The Hornet.
Headphones: Sennheiser HD650, Sony MDR-7506, JH Labs JH16 Pro, Ultimate Ears 18 Pro.
Power Amplifiers: Classé CT-M600, Lamm M1.2 Reference, MBL 9007 (all monoblocks).
Loudspeakers: Vandersteen Treo, BBC LS3/5a, Boston Acoustics…