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Ayre Codex DAC/Headphone Amplifier

Ayre Codex DAC/Headphone Amplifier

The Ponoplayer – Neil Young’s portable high-res digital audio Toblerone – may still be officially unavailable outside of North America, but everyone worldwide can reap the benefits of elements of the design in the shape of the Ayre Codex headphone DAC. Combining several key technological developments put in place to make a high-performance portable player with a balanced headphone output, and the kind of high quality home audio designs Ayre knows so well, the Codex is said to be first in a long line of products in a new stripped-down desktop line.

Ayre’s Codex is a small, AC powered digital converter, with asynchronous USB, and Toslink, digital inputs, and both balanced and single-ended outputs for headphones and line-level amplifiers. It can support signals up to 24bit/384kHz or DSD 128 on USB and 24bit/192kHz through Toslink. There is no line-level input, so it technically can’t be considered a ‘headphone preamplifier’. This means there are both a pair of RCA and XLR output sockets on the rear panel and two 3.5mm and one ¼” TRS jack on the front. The 3.5mm jack sockets can be used as a conventional stereo output for headphones, or as individual channels in balanced operation. Keen-eyed Ponoplayer users will note the same options for the two 3.5mm jacks on the top of their triangular music player. Controls are limited to the two-in-one dial on the front panel and a power switch by the IEC power inlet, and the sum total of display options are a simple red LED panel at the top of the player (very 1970s digital watch) and a single red LED to denote balanced operation. That front volume control is purely in the digital domain, however, and is capable of a full 24-bit resolution in attenuation.

Pressing and holding the volume control for a few seconds calls up a series of instructions: Ayre calls this its menu tree, but with extremely limited display options available, that tree is more like a sapling. Nevertheless, you can change inputs, adjust the output mode (headphone or audio system output), alter the display brightness, or display the firmware version. The 3.5mm jacks have auto-sensing; if only one headphone jack is inserted, the Codex defaults to standard single-ended stereo mode, but if a second is inserted, the Codex ‘asks’ if there are two headphones sharing the same input or balanced left and right-channel connections from a single headphone.

Through all its products, Ayre deploys a ‘Four Treasures’ approach to design; devices must be zero feedback (for a more realistic, tube-like sound), fully complementary (no coupling capacitors or transformers in the signal path, featuring Ayre’s EquiLock circuitry for active gain devices), fully balanced (more for immunity from power supply ripples, rather than low noise across long cables), and built with a high-quality power supply (Ayre’s own AyreLock linear supply allows no ingress of RF or EM interference from the wall). This applies as much to the Codex as it does to the company’s top preamp and power amplifiers. The Codex also features the company’s ‘diamond’ output stage (a clamp circuit from the early 1960s that was all but overlooked ever since). In other words, except for the matt-black but well-built case and the use of letting in place of seemingly random legends to describe functions, this is every inch an Ayre product.
Almost – it runs hot to touch like an Ayre amplifier (nothing to worry about here) but it doesn’t take half a year to run in (nothing to complain about here).

Having recently dropped the QB-9 DAC, Ayre’s only digital front ends are the Codex and the considerably more upmarket QX-5 Twenty hub, so the Codex plays very much a dual role in the company’s line-up. Granted most people will use the Codex as a standalone USB headphone DAC, and have it sit on the desktop near their computer, but there will be a significant number of people who always wanted a QB-9 for their home system, and may never use the headphone outputs. Then, there will also be the hard-core headphonistas who look at this as either a Ponoplayer for the home, or a useful entry point for balanced operation. Ayre needs to address all these disparate potential clients if Codex is to shine. And, unlike when the QB-9 walked the earth, the competition has raised its game in the last few years.


Addressing the ‘several buyers, one DAC’ aspect is easy, because the Codex is extremely consistent. The sound you get through a set of balanced headphones is functionally identical to the sound you get from the same headphones with the cables replaced for one single-ended 3.5mm TRS jack. This is hard to do in the UK; Ponoplayers being thin on the ground in the UK means Pono-ready balanced connections are less common here, so a kludgy XLR-3.5mm jack socket-short pair of male 3.5mm-3.5mm cables was in order. The move from single-ended to balanced (using a pair of trusty but a generation or so out of date HiFiMAN HE500) is justified by a degree of additional transparency and detail, with no noticeable tonal shifts or balance changes. Moving from headphones to stereo system had the same tonality. This consistency is a mark of a company that understands both the headphone and loudspeaker worlds equally well – Chord achieves the same consistency in the DAVE (see page 20), but most rivals seem to be either amp makers dabbling in headphone design, or headphone experts with vestigial amplifier connections. The fact Codex has its feet firmly planted in both camps may not be a deal-maker for many, but the consistency is well appreciated.

The interesting part of the Codex performance, from the perspective of someone who knows their way around the Ayre sound, is that it doesn’t sound similar to models like the QB-9 at all. Tonally, the Codex is warm, rich, and inviting sounding at the treble, where Ayre is often considered clean and bright in the top end. However, what they both share is a fluid, transparent, and extremely dynamic midrange, and a strong, stentorian, deep bass. This can be so clearly heard on ‘Pretty Pimpin’’ by Kurt Vile [B’lieve I’m goin down, Matador], with Vile’s delicate tenor/countertenor voice and simple guitar parts underpinned by a thumping bass line. Although less compressed than other tracks on the album, this is a recording that doesn’t benefit from lots of stark high-frequency detail, and that makes it sound sonorous and beautiful through the Codex. However, the track also needs a lot of mid-band fidelity and articulation, because Vile’s laid-back Pennsylvanian speech patterns and his in-the-round poetic style are almost like a Southern drawl to English ears and sometimes hard to define. And it’s here the Codex does wonders.

I also tested the Codex with a pair of Nobel Kaiser 10 custom-fit in-ear monitors, primarily because working with CIEMs is an exercise in noise-floor testing, and it’s here that maybe Ayre’s strongest suit shines through. This is one of the quietest AC mains powered headphone amp/DAC designs out there, serving up a whisper-quiet background normally reserved for the likes of battery powered Chord Hugos and such. The Codex has lots of power in reserve for driving more demanding headphones, but at the quieter end of the spectrum, where late night listening with extremely sensitive headphones and IEMs could leave you cold from fighting the noise floor, the Codex does just fine.

But perhaps the most attractive part of the Codex is that inviting sound. It’s rich, but not too rich. It’s not like a billionaire dipped in chocolate fudge, but instead has that harmonic structure and tonal insight that people crave from good audio. Never so rich that it could be mistaken for being tonally ‘heavy set’ or ‘thick’ across the midrange, but instead possessed of the kind of tone that makes many good DACs seem a little ‘lean’.


The Ayre Codex is an important product for the brand. It’s the first model that the company has made that leverages the performance of the Pono. It’s the first Ayre-branded headphone design, the first in potentially a new line of lower cost desktop audio components. It’s now Ayre’s entry level digital source component, and something of a gateway into the brand’s products for many prospective newcomers. And it achieves all these goals with equal aplomb. While it may be warmer-sounding than Ayre ‘proper’, it’s an incredibly inviting and easy to like sound. Whether this is your first venture into top-notch audio, your first Ayre product, or the first – and last – line in your desktop audio chain, the Codex does it all so well it’s hard not to love it. Highly recommended.


Type: DAC with headphone amplifier

Inputs: USB and Optical (Toslink)

Headphone outputs: Two 3.5mm mini-phone jacks.
One ¼” phone jack. 3.5mm mini-phone jacks configurable to balanced mode.

USB features: Asynchronous transfer mode for USB input. DSD or PCM input over USB.

Formats supported (USB): PCM 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz, 352.8 kHz, 384 kHz (up to 24 bits), DSD64, DSD128

Formats supported (Toslink): PCM 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz (up to 24 bits)

Filter: Minimum phase digital filter, single-pass 16x oversampling.

Output Level (Headphone or Preamp Mode): 7.0 volts balanced, 3.5 volts single-ended

Output Level DAC Mode: 4.0 volts balanced, 2.0 volts single-ended

(W×D×H): 25.5×23×13.7 cm

Weight: 1.4 kg

Price: £1,695

Manufactured by: Ayre Acoustics


Distributed by: Symmetry


Tel: +44(0)1727 865488 


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