I subscribe to the belief that the iPod is not a source for serious music listeners when played over a high-end system. Although an iPod is capable of storing vast amounts of bit-perfect digital music, the sound quality of its analog output leaves much to be desired, at least from an audiophile's perspective when connected to a good sound system via a typical analog iPod dock. The iPod's digital to analog converters (DACs), though not flawed, simply offer less-than-ideal sound quality for demanding listeners. Listening to iPod music on a high-end system reveals its shortcomings, particularly in detail and clarity.
Wadia 170i Transport
But I take it all back. I (and other audiophiles) have been proven wrong with the Wadia 170i Transport. The 170i is a unique iPod dock that plucks the iPod's digital output, bypassing the player's internal digital to analog converters (DACs). Every other iPod dock taps the analog outputs, not the digital output, making them little more than a convenience item since an iPod can be connected to a stereo via an analog cable from the headphone output to a line level audio input.
Tapping the digital output from an iPod is huge. The iPod is simply a storage device and retrieving the best sound quality means tapping the digital output and processing it through an external DAC, such as the digital inputs on a receiver, AV processor or outboard DAC. The D to A converters in these components likely exceed the performance of the DACs built into an iPod and produce sound quality more suitable for playback on a high-end system.
The Wadia 170i is a small, understated black (or silver) box measuring 8" wide, 8" deep and less than 3" high with the iPod dock on the top. It has a coaxial digital output, a pair of analog outs (for backup and recording to analog devices), S-Video and Component video outputs for connection to a TV (usable with iPod video models). It has a remote control for basic iPod functions (play, pause, next/previous track). All other functions are controlled via the iPod's click wheel.
When an iPod docks to the 170i, it is automatically in 'extended interface mode', which activates the digital output of the transport. Pressing the 'mode' button on the remote control, which also activates video output, disables the digital output and enables the analog outputs. The iPod must be un-docked then re-docked to return to 'extended interface mode'.
Bryston BDA-1 Digital to Analog Converter
It's important to emphasize that the Wadia 170i must be connected to a component with coaxial digital inputs, such as a receiver, AV processor or outboard DAC. In this review, I enlisted the support of the Bryston BDA-1 Digital to Analog Converter, one of the best high-end choices in DACs. Although this review is about the Wadia 170i, the capabilities of the Bryston BDA-1 cannot be overstated. It's a full-featured DAC with digital inputs for as many as eight sources (1-USB, 4-coaxial, 2-optical, 1 AES/EBU input) and it supports multiple sample rates from 32 kHz to 192 kHz and up to 24-bit signal resolution. The BDA-1 features upsampling up to 192 kHz, depending on the sample rate of the source.
A Caveman Can Hear the Difference!
This statement may be over the top, but honestly it doesn’t take a highly trained ear to hear the differences between the digital and analog outputs of an iPod. It requires little more than a few A-B comparisons to hear what you've been missing. "Live in Paris", one of Diana Krall's knockout performances was my first realization of what I really had stored on my iPod. The openness, detail and sense of space, suppressed by the anemic DACs in my iPod were released when listening on the 170i dock. The improvement was no small potatoes. The analog output sounded veiled and somewhat edgy compared to the clean, open, smooth and detailed sound of the digital output. In particular, sibilance was noticeably smoother on vocals and cymbals. The Wadia 170i doesn't add anything to the music or equalize the sound – it simply extracts the bit-perfect digital music stored on the iPod and external DACs convert digital data into analog sound. Make no mistake; the 170i is just another me-too iPod dock without a good set of DACs. The Bryston BDA-1 DAC is one of the best I've heard and certainly has the best connectivity. The sound quality of the Wadia/Bryston combo ranged across formats and data rates. I imported the same tracks from 'Live in Paris' in AIFF format (CD quality 44.1 kHz, 16-bit, 1,411 kbps) and MP3 format (128 kbps) and the 170i/Bryston produced excellent results with both. Unfortunately, importing music at the highest data rates chews up space. Ripping CDs to iTunes in AIFF format consumes 10 MB/minute and severely limits my 4 GB iPod Nano, but it pays off at the other end.
Conclusion & Specifications
The 170i elevates iPod music to a quality appropriate for higher end audio systems and opens new opportunities for using an iPod. The biggest revelation happened when I realized that the iPod could be used as a mini music server for high-end audio systems. In fact, the quality of the Wadia 170i and the Bryston BDA-1 could cause me to move my CD player off the shelf, replace it with the Wadia 170i and the Bryston and store my CDs in the closet. I could store a lot of music on a iPod with sufficient storage capacity. The Wadia 170i is the conduit to access them in true high fidelity. For now it appears that the Wadia 170i is the only iPod dock offering true digital output from an iPod. This is a huge deal, expect more to follow.
Wadia 170i Transport
- Digital Output: Coaxial S/PDIF (RCA)
- Analog Outputs: Single-Ended Pair (RCA)
- Video Outputs: S-Video
- Component Video (RCA)
- Dimensions (W x H x D): 8 in. x 2.7 in. x 8 in.
- Weight: 2.42 lb.
- Available in Black or Silver
- Price: $379.00