For those not in the know, the iPod (iPhone; iPad) is capable of storing music at essentially the same quality level as CD (or whatever source you use). To achieve this, use either ALAC (Apple Lossless), or WAV. However, regardless of storage quality, the iPod's limitation has been its necessarily compromised DAC - the part that converts the digital recording back to analogue signals we can listen to. Marvel of miniaturisation though it is, there is only so much you can do - with current technology - within a package this small.

The answer came some years ago with Wadia's 170i iPod "transport". This Apple-approved device retrieved the information "bit-perfect" from the iPod, passing it straight out as a digital signal to the DAC of one's choice. Overnight, the iPod became a serious contender as the heart of one's music system, no matter how expensive and exotic might be the following components. Rave reviews followed, helped along by the sheer convenience of being a top-end home system in the evening. Finally, the iPod's potential was fully realised.

Wadia have since released an 'upgraded' iPod transport, the 171i. Unfortunately, both this and the original transport are somewhat expensive. The 170i has had increasing compatibility issues too, as iPod technology advanced. More recently, both Onkyo (NS-D1) and Cambridge Audio (D100) released competing devices at about half the price and, along with the new Wadia, no compatibility issues.

And now we have the PURE i-20, bringing exactly the same bit-perfect digital-retrieval capabilities and up-tod-date compatibility at a bargain price: less than half the price of the Onkyo and Cambridge Audio devices. It manages to do this AND include a much better than iPod-quality DAC (still not a match for most stand-alone DACs though) AND it charges your iPod/iPhone while connected AND it does all this in a versatile, easy to use and relatively attractive and portable package.

How does it perform? Well, bit-perfectly. That is to say, I have found playback from my (lossless), full quality files on my iPod indistinguishable from the same tracks played direct from my CD transport: this with highly resolving, audiophile-grade components following in the rest of the chain, both headphones and speakers. In other words, this bargain-priced transport does exactly what it claims to.

Any flaws? Only the rather tiny, cheap-looking and cheap-feeling remote. Reputedly, the Onkyo remote is much better. This unit functions with a wide range of iPods and iPhones - see PURE's information on their website - but not iPad, which I understand only the Cambridge Audio device happily supports. Some of my fellow owners on Head-Fi lament it's not battery-powered (it runs off a 1.2A 7.5V power pack).

The only other flaw is the risk of compatibility issues over time, as experienced by the first Wadia transport. But all these devices share this problem, something the PURE's much lower price mitigates considerably.

So there we have it: an almost ridiculously cheap source component with the versatility to scale anywhere from a modest travel system (e.g. i-20 and headphones) to any home stereo system regardless of how expensive or esoteric it may be. I love mine, and use it all the time.