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This review first appeared in the July 2011 issue of hi-end hifi magazine fairaudio.de of Germany. You can also read this review of the Ayre 7-Series separates in its original German version. We publish its English translation in a mutual syndication arrangement with the publishers. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of fairaudio or Ayre - Ed.
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Reviewer: Jörg Dames
Sources: Fonel Simplicité, laptop with foobar2000, Northstar USB dac32 or Benchmark DAC1 USB
Amplification: Integrated - Fonel Emotion; pre/power - Funk MTX Monitor V3b, Belles 21A, Audionet AMP monos
Loudspeakers: Thiel CS 3.7, Sehring S 703SE
Cables: Low-level - Straight Wire Virtuoso, Vovox; high-level - HMS Fortissimo, Reson LSC 350
Power delivery: Quantum Powerchord's, Hifi-Tuning Powercord Gold incl. IeGo termination, MF-Electronic power strip
Rack: Lovan Classic II
Review component retail: €3.800/ea.
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Colorado Bros. Once glance at today’s testers and the word brothers seems à propos. Twins might be better yet. Granted, the displays and fact that an amp needs no play and pause button betray which brother is which. But where to put the shiny silver disc might catch a few at hello when first confronted by the Ayre AX-7e and CX-7e MP decks.
If after some checking the CD is correctly swallowed by the CX-7e MP with an expectant push on ‘play’ next, the following glance will hover with uncertainty over the amp controls. Now the question becomes whether this is really an amplifier or more a tool for would-be astrologers where a click of a switch reveals whether moon or stars are in the ascendant [upper right].
No fear, some trial ‘n’ error or alternately a reach for the comprehensive manual create clarity. The four metal controls on the right of the 12.5mm fascia handle source selection, the sun controls the display. What looks like the front of a CD tray controls volume. But enough superficialities. Let’s get inside.
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Starting with the amp, we’ll first brush up on its business end. The block-type Cardas posts with Rhodium-plated high-purity copper contacts and massive non-magnetic stainless steel bolt attract attention for the central wheels which administer equal pressure on each leg but—unless you fancy bananas to turn shape shifters—only welcome spades. There are three RCA and two XLR inputs. Selection of any automatically disconnects all grounds safe for the active source. This undermines potential ground loops and HF noise propagation on the ground plane.
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Volume control circuit | Ayre boss Charles Hansen
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Ayre handles volume with a 66-step resistor ladder of discrete Roederstein metal-film parts to insure perfect channel tracking even at low settings where traditional pots often get confused. With the AX-7e you won’t bring home a brute but there’s 60wpc into 8Ω on tap, twice that into 4 and purely on paper the 16 x 50-watt output transistors would be good for 800 watts. The 400VA transformer flanked by long-life filter caps of 36.000uF capacity appears to be quite traditionally dimensioned given the power rating. Less common is the preference for an apparently simpler EI core over the more typical toroid, the latter often presumed to automatically offer smaller stray-field radiation, lower idle current and higher efficiency. Philipp Krauspenhaar, tech guru at German Ayre import house Sun Audio, wasn't shy to express his own opinions on the audiophile subject of toroidal superiority:
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"True, toroids enjoy a shiny reputation but such common wisdom is often less wise and more common…To start with efficiency, where that’s really top priority—say public utility power—have you ever spotted a toroidal transformer? It’s fair to say that due to less material density for a given power rating toroids occupy less space and weigh less than an equivalent EI core. In cost-critical applications like consumer electronics, this can become an important consideration.
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The board layout gets away without coupling caps, cables or push contracts in the signal path
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"Smaller stray fields are factual too. The relevant point is however that all transformer parameters are greatly influenced by construction methods and size. With audiophile hi-end machines—and particularly those from Ayre—ultimate quality is top priority. Here our special Mercury trafos have major advantages. Distortion coupling effects are significantly lower. Where primary and secondary windings overlap across the entire surface of a toroidal core to act like the layers of a plate capacitor with very high coupling capacitance, Ayre’s transformer lowers this value by more than 90%.
"Our secondaries also use bifilar windings to mostly cancel cross distortion. This works like AC line filtering, albeit without additional parts in the power supply. Due to the higher iron mass EI cores have compared to toroids, energy storage is higher. This acts like a fly wheel. Additionally the magnetic flux in the core is deliberately set below 1 Tesla (toroids are usually 1.5T) to approach the stray field behavior of better toroidals. Finally Ayre’s iron compared to equivalent round transformer cores pulls significantly lower in-rush current. This neatly eliminates current limiters with their additional power supply complexity."
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