The Apple iPod has undoubtedly changed the face of music listening as the majority of music lovers know. It was not the first MP3 player and it's not the best sounding, but thanks to outstanding design and ergonomics it transformed music on the move and has gone on to invade the home as well.

This is achieved with inexpensive standalone sound docks with built-in amp and speakers, or for better results, with docks that allow you to stream the player's analogue output to an existing system. Sound quality is inevitably compromised by a number of factors, but the compact and essentially cheap nature of the DAC in an iPod seems to be one of the biggest.

The second, of course, is users' preference for compressed music files in order to boost the capacity of the device. Downloads also play a part in quality. Realising these limitations, high-end digital specialist Wadia has built a dock that can output a digital stream from an iPod for external conversion.

Design

Wadia is the first and, so far, only company to do this with an unmodified iPod. The only competition that we have discovered comes from MSB Technology whose iLink dock requires that the iPod be modified for the purpose, which is partly why the price of player and dock is considerably higher at £1,900.

The Wadia 170i Transport is almost as stylish as the iPod itself thanks to a compact square case with rubberised spike feet and a high quality anodised finish. The key to its appeal, of course, is the Wadia logo cut into the front, something that is usually only found on components costing over ten times the asking price here.

A variety of dock inserts are supplied to accommodate different models of player and the list of these seems fairly comprehensive, with all but the Shuffle and iPhone present. We would recommend that you go to wadia.com for a definitive list to make sure your player is supported.

Featurewise, the 170i Transport has a coaxial digital output and analogue out on RCA phonos, these sit alongside video out in composite and S-video varieties. The connections are of the same quality that you find on amps and CD players at this price, essentially quite basic and for this reason we would suggest you avoid doing what we did, that is using a high-end chord indigo digital interconnect which has extremely tight plugs.

Wadia supplies a digital interconnect in the box alongside a small remote, but this can only be used to find next and previous tracks in an album or playlist, it has + and – buttons too, but these 'may be used with future Wadia products.'

The final 'mode' button changes output from digital to analogue, but not back again, which can be a trifle irritating unless you know to take the player out of the dock and re-seat it to achieve this end. As mentioned earlier most iPod users compress the music they want to hear in order to get more on the player, this inevitably compromises sound quality and while it may not be so apparent via the supplied headphones in this situation it's obvious.

The format that Wadia's UK distributor MDC recommends is Apple Lossless which compresses files to about half their original size but without an obvious reduction in sound quality. The best system available is WAV which is totally uncompressed and, therefore, takes up acres of space, but if you want the best results and have a system that can take advantage it's space worth using.

Sound quality

We used the 170i Transport with two varieties of iPod classic, a 120GB version of the current anodised finish model and its predecessor, a 5th-generation 80GB example. The latter was used because it's an MSB iLink-modified unit that works in both the Wadia and MSB docks and was used for comparison with that competitor.

Its a comparison which makes a good case for the extra cost of the MSB, in a high-end system the iLink is clearly a superior player and one which can hold its own against CD transports of like price. It has a more open sound, presents more image depth and is clearly more revealing, the 170i Transport seems thinner through the midband and the bass and while not short on grunt, does not go so far down.

With challenging material the Wadia struggles to maintain its poise in a highly revealing system, a job that the MSB is clearly more at home with. It's crucial to remember here that even if you include an iPod classic in the equation, the 170i Transport is a third the price of its competitor. On its own terms the Wadia does a remarkably revealing and entertaining job with both Apple Lossless and WAV files on the iPod.

Tord Gustavsen's Tears Transforming is as captivating as ever in emotional terms and a good deal of its image depth and 'air' is revealed thanks to plentiful detail. With WAV files it sounds smoother and the presentation takes the edge off less than pristine recordings, Gillian Welch's Time (The Revelator) can sound a little edgy when fully exposed, but the Wadia makes it easier on the ear.

A more meaningful comparison was made with Arcam's rDock (£150) an analogue-only dock that can be used with any line-equipped amplifier, which offers full remote control and full display with Arcam Solo components.

Pitting the two against one another using the analogue output reveals a difference that is not slight. The Wadia delivers greater transparency and solidity of sound that makes the rDock seem vague and lacking in resolution. Moving from the Wadia's analogue output over to the coax digital out and plugging this into a Russ Andrews DA-1 DAC represents another leap in quality. Now you have depth of image, precision, bass weight and shape that puts the iPod in hi-fi territory.

Alison Krauss sounds exquisite and her Union Station band positively sumptuous, it's not hard to hear why fellow reviewer Alvin Gold, among others, is so keen on this particular artist. Arguably, the most important test came when we brought in a well-regarded CD player to compare as a transport.

As it consistently performs well, we used a cambridge 840c CD player and took its coaxial digital output to the DA-1 DAC to keep the playing field level. There is the option of taking the Wadia's output into the cambridge's digital input, but that would favour the disc spinner. Here the 170i Transport met its match, the cambridge turns in a slightly more relaxed and refined result that means you can hear more and play louder without discomfort. But given that the 840c is so well-regarded and more expensive, the difference is not that big.

The Wadia 170iTransport is a remarkable piece of kit. it sounds extremely good given that it works with a mass-market source and it can give a fully badged-up CD player a run for its money. If you already have a compatible iPod and fancy using it as an audiophile music server this is the most affordable way to do it.

Anything that can turn such a popular device into a piece of hi-fi is impressive and this does a spectacular job for the price.

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