Sending music to DAC wireless vs wired

Depending on bandwidth, distance and network type.

If the wireless router is fairly far way or going through many walls, signal will drop enough and there will be some drop outs.

If the network is full of other traffic like downloading large files and etc, it will also slow down enough to have drop outs.

Wifi-N network is much better but all network connections should be the same network to keep the same speed. Mixing network might slow some router down.

The new Sonos has an excellent wifi solution for wifi. Check it out. It uses a propritery network system instead of typical wifi.

That's probably not a good question to ask then if you are concerned about electrical isolation.

That depends much more on the exact DAC and interface used from media player/HTPC -> DAC.

For a simplified example, toslink automatically removed the electrical isolation issue but leaves much to desire on the jitter front. A regular BNC 75ohm coaxial cable will do much better at the jitter front but does carry the ground over. So if the DAC and media player has a good noise rejection circuit with a decent power supply, that would be prefered.

Regarding signal/noise issue on wired and wireless, any decent Cat5E ethernet cable system is great at noise rejection. Cat5E can transmitt 1gigabit/sec over 100ft easily without signal loss. That's far greater bandwidth than any DAC at 24bit/192Hz and any existing Wifi Network.

Did not know that isolation transformers are used in the digital input. I thought it can be used rather easily in the power supply but anyone can do that cheaply.

I figure that most of media players have rather inexpensive computer power supply so most of the ground noise is coming from the supply line instead of the nicer DAC.

Any inexpensive ones? Meaning <$1k. I figure it would rather expensive to implement a transformer for a digital signal.