Aardvark In-line RJ45 Filter –

Earbuds for your Ethernet?

By Roy Gregory

Network applications are becoming more and more widespread in audio systems, for file replay, system management, source integration or simple remote control. Along with the convenience and flexibility this has engendered, has come a belated recognition of the downsides that come along with hooking up your audio system to a computer network and all its associated hardware. Finally, audiophiles previously besotted by the idea that file replay could free them from the tyranny of expensive hardware (after all, the best and most powerful computers still cost less than a single high-end audio product) have started to turn a more cynical – or should that be experienced – eye to the computers and network components that allow file replay and ethernet control. “Once bitten twice shy” seems to be one maxim that has escape the collective, accepted wisdom of the audiophile community…

Any discussion of network issues and their impact on audio/musical performance inevitably turns to the question of noise – internally generated or induced. By now it has finally been accepted that the modestly priced switch gear and routers that are used to lace computer networks together might be perfectly adequate for computer use but don’t come close to preserving the data integrity demanded for audio file replay. The cheap, wall-wart power supplies used for most computer hardware generate noise, the switches and router circuitry generate noise and the cables that lace everything together are prone to induced RF noise from the wash of wireless signals that pollute our living space these days.

Networking done right…

In response, there has been a growing tide of ‘audiophile approved’ network components, from simple linear supplies to replace the wall-warts, to expensive, dedicated switches and ethernet compatible cables. When it comes to file replay, infrastructure has become a hot-topic – and deservedly so. Many aspects of the disappointing performance so often delivered by file replay can be traced directly to noise-related issues with the network to which we connect our expensive audio streamers, servers and DACs. The real problem lies in the very nature of digital noise, RFI and what it does to digital signals. In the analogue domain, noise is pervasive and (relatively speaking) fairly benign – witness the continued success of tube amplification. Reducing system noise is definitely a ‘good thing’ but we can remain remarkably tolerant of a surprisingly high noise floor in an audio system. Even ambient noise can be surprisingly tolerable: pause the music in any room at the Munich show and stand under the air-con vent and you’ll see what I mean… But digital noise is different in that rather than simply raising the noise floor, it has a directly destructive impact on the timing and content of the signal, attacking the structure, pattern and content of the music itself. In the same way that we can accept quite high levels of even order distortion but find even tiny levels of odd order distortion intrusive, tiny levels of digital noise can have a disproportionate impact on data integrity and a ruinous effect on musical performance.