I'm also interested.
Do you have a receipt or anything indicating the Digital Mod? I did a search and found this picture and description which says the digital mod includes a 75-ohm WBT NextGen RCA output connector, seen at the right in this photo:
And the description:
"The Digital Only modification is the first level of internal upgrades in the Bolder Cable Company lineup. A Squeezebox with this modification package is intended for use with an external DAC, or in a home theater system where a digital to analog converter is housed in another component. Every Bolder modification package starts with an upgrade to the internal power supply stage of the Squeezebox. All of the power supply capacitors are replaced with a combination of Panasonic FC or Blackgate NC capacitors. Since the internal power supply distributes the current to all the circuit stages in the SB3, these upgrades improve both the digital and analog stages of the Squeezebox. The second half of the digital modification addresses the architecture of the digital output circuit. In the stock SB3, the output of the digital buffer passes through a circuit containing various parts, which includes several inductors and complicated board traces. Wayne has bypassed this portion of the Squeezebox, and installed a proprietary 75-ohm wire, and a 75-ohm WBT NextGen RCA output connector. Now the SB3 has a true 75-ohm output level, which the optimal configuration to interface with a separate digital to analog converter."
