Wadia has an update coming out for their wadia iPod dock. The existing wadia dock is one of the few that outputs pure digital for external DACs. Here's the info they sent me about their new version of the dock:
Thank you for your interest in the Wadia iPod transports.
The 171i will have the following features above the 170i: • Better internal power supply. • Audiophile grade connector for the coax digital output. • TOSLINK optical output. • Metal remote with menu controls for the iPod/iPhone. • Higher grade circuit board. • Better clock for lower jitter. • Licensed for iPhone. • Power indicator light.
The 171i will not be able to display the menus and the album art with the video out.
The 171 should be available starting in September and will retail for $599. The 170i will continue to be made.
Please feel free to contact Wadia if you have any other questions or comments.
Customer and Dealer Support Wadia Digital www.wadia.com
Another alternative is the Onkyo ND-S1 Transport, which is also a digital pass through. You can pick one up on eBay shipped from Japan for about $180 new (it works with US voltage). Haven't compared it yet to the 170i or the newer 171i.