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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.
The 170iTransport is an 8-inch square that's 2.7 inches high--certainly bigger than most iPod docks we've seen. Its silver powder coat aluminum chassis looks like a miniature, mega-buck Wadia component. The chassis doesn't have any controls, but the included remote has Play/Pause, Next Track, Previous Track, buttons, and a Mode button that toggles between the 170iTransport's digital and analog outputs. The Wadia's remote let us skip through songs on a given playlist, but to access other playlists we had to walk over to the 170iTransport/iPod and directly navigate the Nano's menus.
Wadia offers a range of D/A converters, but right now the least expensive model, the 521, runs $6,950 MSRP. That said, the company is developing a matching 170iTransport D/A with an expected MSRP of $1,000 or so. It should be out sometime early next year. If you can't wait for that model, check out Benchmark's highly regarded DAC1 ($975).
We didn't have access to those elite Wadia or Benchmark D/A converters, and even if we did, we'd learn more about their sound than that of the 170iTransport. Thankfully, any AV receiver equipped with a coaxial digital input will suffice. We plugged the 170iTransport's digital output into our Onkyo TX-SR805. It may not be high-end, but the Onkyo's D/A has to be a lot better than the one built into the iPod.
We compared the sound of CDs played over our Pioneer DV-45A DVD player to a third-gen (fat) iPod Nano loaded with AIFF and WAV files of the same music played through the 170iTransport (listening to both over high-end Dynaudio C-1 speakers driven by the Onkyo receiver). With every album--from artists such as My Morning Jacket, The Black Keys, Willie Nelson, and Wynton Marsalis--we heard no difference. The CD player and Nano sounded exactly the same.
We next compared the sound of the CDs with the "naked" iPod, by plugging the music player into an Apple dock that was, in turn, plugged into the Onkyo's analog inputs. We can't claim we heard "day and night" differences, but we definitely preferred the sound with the Wadia dock. The clarity/airiness were superior, and the solo iPod added some fuzz to the sound.
Please note: older iPods won't work with the 170iTransport, or they'll work with diminished features. For instance, first-gen iPod Nanos will output digitally, but the menu won't be displayed and the clickwheel won't work. That means you pretty much have to start a playlist playing before you dock the player with the Wadia. Newer iPod models provide full access and functionality. Be sure to check Wadia's FAQ before purchasing. (At the time of this writing, it hasn't been updated to include data on the latest September 2008 crop of iPod models, but Wadia has confirmed their compatibility and said that the site will be updated accordingly in the near future.)
As far as alternatives go, it's worth mentioning that you could get the same basic effect delivered by the 170iTransport by playing your digital audio files via the digital output of a PC audio card, and taking the iPod out of the equation altogether. Likewise, we assume the $600 Escient ZP-1 redigitizes the iPod's analog audio before it hits that unit's digital output (giving you an extra--and undesirable--D/A and A/D cycle), but we much prefer that unit's full on-TV display for navigating the songs on the iPod. Of course, its list price is about 50 percent greater than that of the Wadia.
Still, the Wadia 170iTransport is intended for persnickety audiophiles who want the highest quality sound, and by that measure, it delivers the goods. It's recommended for seriously discriminating listeners who appreciate the difference between uncompressed/lossless and lossy digital files, and who have the high-end equipment (serious D/A converters and excellent speakers) that will make the best of the 170iTransport's all-digital output.