Apple TV outputs 48kHz while CD rate is 44.1kHz. Translation between two affects the sound. I use AirPort Express at 5GHz - no dropouts. 5GHz is much better for wireless because is not as common as 2.4GHz(Bluetooth, Computer, Microwave, Cordless phone etc), has a lot of channels (23 vs. 3 non-overlaping channels) and penetrates walls poorly - not important when router is in the same room but greatly helps to reduce outside interference.
Airport Express has decent jitter (258ps p-p). I use it with jitter suppressing Benchmark DAC1. Even better solution would be to get reclocker between receiver and the DAC. AirPort Express is limited to 44.1kHz but pretty much all my music is 16/44.1 Higher bit rate or more resolution might be better but only if music came from original master tapes and is not upsampled 16/44.1kHz (often the case) that my DAC is doing internally anyway.
Beauty of wireless connection is that nothing before receiver makes any difference. Playback program, computer speed, amount of memory etc. are not important since music is sent as data without timing. Timing is recreated on the other side of the bridge. As for Raid - I prefer just simple backup (have two). Simple backup, unpowered, won't fail, can be stored at different location (fire, theft etc). I keep one copy at work. Mirroring Raid is nice if you change data often but in case of virus or controller failure you might loose both copies. Another option is to use, if you got MAC, Time Machine for backup (but it will give you only one copy). I would keep HD off - it will automatically create new backup when powered.
Airport Express has decent jitter (258ps p-p). I use it with jitter suppressing Benchmark DAC1. Even better solution would be to get reclocker between receiver and the DAC. AirPort Express is limited to 44.1kHz but pretty much all my music is 16/44.1 Higher bit rate or more resolution might be better but only if music came from original master tapes and is not upsampled 16/44.1kHz (often the case) that my DAC is doing internally anyway.
Beauty of wireless connection is that nothing before receiver makes any difference. Playback program, computer speed, amount of memory etc. are not important since music is sent as data without timing. Timing is recreated on the other side of the bridge. As for Raid - I prefer just simple backup (have two). Simple backup, unpowered, won't fail, can be stored at different location (fire, theft etc). I keep one copy at work. Mirroring Raid is nice if you change data often but in case of virus or controller failure you might loose both copies. Another option is to use, if you got MAC, Time Machine for backup (but it will give you only one copy). I would keep HD off - it will automatically create new backup when powered.