Alternatives to streaming via Apple TV/iTunes


My current 2 channel setup in the main living room is as follows:
iMac (iTunes) --> Apple TV (via Airplay/wifi) --> Parasound P5 (via TosLink) --> Parasound A21 (via XLR) --> B&W CM10

I usually buy CDs and rip them (using ALAC) into iTunes.

I don't really have any major complaints, but I often wonder if this is the most optimal route given the rest of my system. I don't want to do a CD player for various reasons.

I've heard folks using a Mac Mini to preamp/DAC via USB, etc. Alternatively, I see dedicated music servers/streamers but some of them sound quite pricey. I'm not sure if dedicated streamers will be a major step up compared to the Apple TV.

I guess I'm interested in finding out if (a) there are better options out there (no CD player though), and (b) if the difference in SQ will be enough to justify the extra effort/expense?

Another thing I often wonder is, if I plan to play music via my computer (or streaming services ala Spotify, Tidal), do I really need to keep a dedicated preamp such as the Parasound P5? I don't think I'll ever do a dedicated CD player source or turntable.

Any advise will be much appreciated.
arafiq
Steve, thanks for some good suggestions. Since I recently made some major purchases (speakers, amp and preamp), I am very sensitive to laying out anything upward of $500-700 at this point, so a dedicated server is probably not going to be on the horizon for a while.

Buying a relocker is not a bad idea. I'll probably look into this. By the way, have you looked at BlueSound:
http://www.audioadvisor.com/prodinfo.asp?number=BDNODE2

Looks quite promising. I'm very interested in hearing your take on it.
USB is a great tool to transfer your digital media files to other devices, like smart TVs, streaming boxes. If there is some issues because of different audio formats, you can use Apple Music Converter to convert all audio files to MP3, FLAC, WAV, AAC, M4A and M4B so that you can store them to USB drive and play them on any device as you like. 
Just realized I could throw my .flac files on a thumb drive and play through the smart tv > optical cable > DAC.
Imagine that, need to read more of the forum input...*laffs