Without doubt, the iPod is a phenomenon; it's easily the most important audio device of the decade. Most buyers use them as convenient portable music and video players, but the iPod's also begun to make its mark on the audiophile crowd--that hard-core golden-eared elite who avidly reads Stereophile magazine, and may even own $10,000 vacuum tube amplifiers and $20,000 speakers. That's where the Wadia 170iTransport comes into the story. Wadia claims "the 170iTransport is the first ever component specifically designed to transform your iPod into a high-resolution audio/video media server." It's available from selected audio dealers for $379.
First, a bit of perspective on how a true audiophile views the iPod (and digital music in general). The iPod--and iTunes--is largely resented by the audiophile community because it popularized listening standards at sub-CD quality, thanks to lossy codecs such as MP3 or AAC that were often encoded at low bit-rates.
Of course, as the storage capacity of iPods increased, more serious listeners realized they could digitize their music in better-sounding formats such as AIFF, WAV, or Apple Lossless. With their iPod thus loaded up with high-quality digital music, audiophiles have been listening with pricey Etymotic, Shure, or Ultimate Ears in-ear headphones plugged into their iPods. Some even go for full-size over-the-ear Grado or AKG headphones.
But few audiophiles plug their iPods into their hi-fi systems, mostly because they were frustrated by Apple's refusal to offer digital outputs for iPods. Up until recently, the 30-pin dock connector provided analog-only output from the iPod, meaning that--to date--every other dock on the market has used the iPod's built-in digital to analog (D/A) converters. But the 170iTransport instead sends your iPod's pure digital stream straight to your AV receiver (or preamp/processor), where that unit's onboard D/A circuitry handles the conversion.
In other words, an iPod docked into the 170iTransport doesn't make a sound. The Wadia simply outputs the raw digital audio data to an outboard component, and the quality of that unit determines the sound you get. So, audiophiles who've spent thousands of dollars on their receivers, processors, and speakers get to maximize those investments--rather than rely on the iPod's internal D/A converter.
(Note that some other high-end iPod docks offer digital outputs, but they presumably take the iPod's analog output and redigitize it--so you're not getting the original unmolested digital data.)
While the all-digital coaxial output is the 170iTransport's reason for being, it does include some other features as well. It can output iPod videos via its composite, S-Video, and component jacks. That said, we were disappointed that there's no onscreen menu on the TV that mimics that of your iPod, so you can't navigate videos from the comfort of the sofa.
The 170iTransport also sports a pair of analog RCA outputs, which are in turn fed by the iPod's built-in D/A converters. It pretty much obviates the reason anybody would buy the device--any $50 iPod dock will give you the same feature--but at least it provides connectivity to analog-only components in a pinch.