Suggestions on Better Server Setup than Mac Mini

Build your own, Buy the Clock Cards, USB Cards from SOTM. Use HDPlex Power Supply, Optimise the computer as best as you can. Alot of info on computeraudiophile site. I did this and it outclass my 10K Server.

mahler123 - As I posted above, dBPoweramp (not free, but reasonable) will batch convert files (I have never had any ALAC files to convert, so I guess the OP should check this prior to purchase).  It will take some time, but it is a "set and forget" operation.

It's amusing to read posts here from people who are suggesting tweaks to the OP to improve the sound, when the OP has made it clear that sound isn't the issue, but reliability.
  The OP is fed up with trying to make a computer work as a music player and he/she isn't alone.  I also did the Mac& Dac route and have ditched it after a couple of years for a dedicated server.  Bluesound isn't perfect but on the whole has given me a lot less frustration than my previous set up.
  If the OP still has his original CDs, the simplest solution would be to buy something like Bluesound and re rip them.  If not, I am wondering if ALAC can be converted to FLAC.  Bluesound will recognize his current files and play them but I am pretty sure they need to be in FLAC

I have tried almost everything (pc/win, Mac, streamer, Jriver, dbpoweramp, iTunes, etc. just to name a few -- audirvana on a Mac that has been simplified down (headless operation) is hands down the best value for audiophile grade (cost is no object excluded). I'm using Resolution Audio Cantata DAC (also supports upnp which I have not tried due introduction of network jitter). Especially with the audirvana iPad app it's great.  Audirvana on a Mac mini is extremely stable/ reliable and if you're having issues it's likely due to needing some maint/updates, disk rights verify/repair (specific to Mac OS file system), or a reinstall of OS X.   Don't bother with iTunes - it makes your library difficult to use with any other down market systems like Sonos, Roku, slim, etc. you may want to use elsewhere in your home. Plus it's much easier to manage files of differing grades (44.1 vs HD or Dsd) for different players in your home (or mobile devices) on a NAS.  That way you can keep audiofile grade files in separate folder - audirvana will pull in to library from multiple source folders.  After all this, I recommend simply managing your audiophile grade files very persistently and just simply using the Apple Music streaming service anywhere else you need music. Regarding audiophile grade source files, I either buy from hdtracks in 44.1/16-24 bit or higher in AIFF or if not available I buy the cd and rip it using EAC exact audio copy.  Once ripped, I've had great success with MediaMonkey for managing file tags and album art.  From many A/B comparisons I've done, AIFF sounded best compared to flac  (I also found aiff equivalent to wav, but wave not taggable). The next level would be to use an SSD drive and external power supply (see mojo products for Mac mini).  This is a very broad and complicated topic that with some key principles can be demystified and simplified for great results. so feel free to PM me if you would like to have more details. I'm traveling, so I can post some links in a few weeks for the Mac setup points for trimming it down. 

One thing about the Mac Mini is you can improve the sound  by adding a Uptone Audio Regen and Audioquest jitter bug. Total cost: $225.

Just build your own.

Happy Listening.

FWIW, I use a Vortexbox Appliance, available from Little Green Computer.  It runs on Linux and uses FLAC files.  To batch convert your music to FLAC, I recommend dBPoweramp.  I currently stream the Vortexbox over my home WiFi network to my Squeezebox Touch, but I am sure other streamers will work, as the Vortexbox is DLNA compliant.  I think there is a list of compatible gear at the Vortexbox forum.  This is a very economical way to go, if not necessarily the ultimate in performance.  But I can't complain - my files sound great on my system.

The Mac Mini with Audirvana already sounds pretty good, so a set up from there must sound awesome.

Questions:

• Converting Mac mini into OS X server - best way to do this, step by step instructions, and how does this affect the itunes library file?
• If I have downloaded itunes in addition to ripped music files, does this affect playback?
• If I download itunes files in the future how does that work?
• With your music server - isn’t that essentially a storage device too or is it just pulling from the OS X server and a bridge to your dac?
• The Mac Mini is currently set up to play on a dedicated system as well as thru our Sonus system elsewhere in the house. How would this transition affect that? Would Sonus still be able to pull from the OS X server?
  
• How are you playing tunes, with what app (currently I’m using the Apple Remote app)?
  
• What else am I missing?
  

Mac mini using iTunes sucks! When I switched to audirvana 2.x I switched from an iTunes library to the audirvana library, much better. 
I thought it was very good until I heard and evaluated dedicated music servers, and ended up getting the Auralic Aries, much better than the Mac mini / audirvana setup. I converted the Mac mini into an OS X server with 20TB of raid disk to store my audio music and other shared data. 
After the Aries, I moved up to the ps audio directstream with bridge ii and it is much better than the Auralic Aries and with my other dac using USB. The bridge ii uses the i2s interface internally between the bridge and dac

wouldn't he have to move all files to a Pi?

BTW, OP how many files are involved?

Consider an RPI3 with a Digi hat to read the data from a NAS or USB hdd.  I assure you, it will sound better than a Mac Mini or USB out from a PC to your dac.  Use Rune, Moode or equivalent as software.  This is all very cheap but fantastic sound quality.  Rpi plug-n-play players are out there and they should play ALAC files.

I agree that dedicated server is more "elegant" solution, but Mac Mini, that I use, is not bad at all.  It is pleasure to use IMHO, at least for me, have very little software issues, is very secure and rock solid (in comparison to Windows).  I assume that USB on the Ultra Fi Dac is asynchronous.  In such case computer timing is not important and it can be used as home computer for other tasks at the same time.

@cdc2 .. many of us have dumped our computers for dedicated streamers. There are some very good options at every price point. IMO a streamer is a more elegant solution. After years with a Mac mini based audio system I bought a Bluesound Node 2. It’s been over a year now and I’m still very happy I went down this road.

I'd stick with the mini as you may need to convert every track on there - dunno how many you have but I have in the 20k range

you could try to find a more reliable player - some are buggy

do you have DSD or is it all Redbook?

ask at
www.computeraudiophile.com/

I am not familiar with ultra Fi but you could switch to a more reputed DAC

Chord, Benchmark, Bryston, NAD, Schiit or Holospring

there is s nothing badly wrong with the Mac mini and iTunes - like most computers you get crashes from time to time. Chrome browser was a problem for me on the MAc Mini but on a PC it will be something else....

ALAC - apple lossless

FLAC files?  or what?

you don't have to let Apple update either...