Ayre Codex DAC/Headphone Amplifier

Headphone amps and amp/DACs
Ayre Acoustics Codex
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.

blog comments powered by Disqus

Featured Articles