Room to branch out comes via a digital input on the 4HD. Olive touts the internal DAC as best-in-breed and the digital input allows users to connect a computer to the 4HD and use the 4HD's DAC. I can visualize a friend bringing an iPod over to the house and connecting it to the 4HD via the Wadio i170 with a little S/PDIF coax to TosLink converter. Very nice feature. Plus, readers who've already invested heavily in a high quality DAC can still use this DAC because the 4HD offers optical and coaxial digital outputs in addition to analog outputs. Olive also supports an iPhone remote control with full album art much the same as Apple's iTunes Remote application. Click on the image below to visit the Olive site, read all the details, and view some really nice photos of the 4HD.