I'm considering adding a SB3 or Sonos to my Bryston BP-25DA, which allows for two digital sources. I've been researching for a couple months on this topic and found several reasons why CD transports may sound different from streaming sources:
- Power supplies: Better power quality = better sound. The stock SB3 may have an inferior power supply to a high end transport. Even modified linear SB3 power supplies may not fully match the careful planning and routing of power in a top transport.
- Impedance matching: Poor matching = reduced performance. It's possible that the transports have an isolation transformer to better match to the recommended 75 ohm impedence. Impedance mismatches can cause jitter.
- WiFi - WiFi is great as a wireless convenience solution, but it is certainly not an optimum signal transfer mechanism. Almost always better to use a hard-wired Ethernet connection for streaming files.
- The computer. If the data source is not a dedicated music server, it's possible to get an audio performance hit if the CPU is nearing the multi-tasking limits. Network attached servers seem to be the best current solution.
What I have not seen as a plausible source of difference is the use of a hard drive vs. an optical drive. Optical sources are inherently less reliable than hard drives, that's why CD encoding contains so much inherent error correction. But, a hard-drive with an overworked CPU could be a problem.
- Power supplies: Better power quality = better sound. The stock SB3 may have an inferior power supply to a high end transport. Even modified linear SB3 power supplies may not fully match the careful planning and routing of power in a top transport.
- Impedance matching: Poor matching = reduced performance. It's possible that the transports have an isolation transformer to better match to the recommended 75 ohm impedence. Impedance mismatches can cause jitter.
- WiFi - WiFi is great as a wireless convenience solution, but it is certainly not an optimum signal transfer mechanism. Almost always better to use a hard-wired Ethernet connection for streaming files.
- The computer. If the data source is not a dedicated music server, it's possible to get an audio performance hit if the CPU is nearing the multi-tasking limits. Network attached servers seem to be the best current solution.
What I have not seen as a plausible source of difference is the use of a hard drive vs. an optical drive. Optical sources are inherently less reliable than hard drives, that's why CD encoding contains so much inherent error correction. But, a hard-drive with an overworked CPU could be a problem.