Ahhhh... then have you looked at
Synology Inc? All their models seem to have an iTunes server. Reviews on their iTunes server aren't very plentiful, but what few there were seemed positive enough.
I'm not sure that device can sync AppleTV units. It appears to function as a a 'shared library' which may or may not appear on AppleTV as a shared library, but probably can't sync it as the primary device and of course certain functions like My Photos need a primary device to stream from. Otherwise you have to store it locally on the AppleTV and frankly, they don't make one with a large enough internal hard drive. Beyond that, I need to run Signal and/or Remote Buddy to control the system from my iPod Touch using AirTunes controlling the Mac iTunes from remote. Otherwise, I have no remote control for my upstairs audiophile music-only system which has no monitor to display the AppleTV Interface.
In short, the device needs to run Mac apps like Signal on top of a full blow direct iTunes. I don't think there's any NAS device that can do that. Squeeze Center devices run straight off an NAS server. Therefore, the remote has to be 'smart' and costs like $300-400. Now when the iPhone 2.0 software comes out tomorrow, that new app that will run on an iPod Touch that can control iTunes might change that equation, but I've been running this system for 6 months or so now and there was no indication such an app would be available and even today whether it could control a remote NAS iTunes shared library (highly doubtful). If an iPod Touch could directly transmit to Airtunes devices, I could have just bought two 32GB iPod Touches, compressed the libraries down to 256kbit (still couldn't fit everything, though but I don't want 128kbit compression) and then directly beam to the AppleTV's Airtunes function and not need a Mac at all. Similarly, I could either use the 160GB AppleTVs with highly compressed music (iPod Touch wouldn't work once again, though) and avoid using a Mac at all at least not having to leave it running.
But my guess is you really didn't want purely an iTunes server, or anything that your Digital Audio might end up doing. You wanted a project and it would be great if it turned out to serve some useful purpose.
Well, I've wanted a way to access my 365+ CDs for a few years now without having to dig the discs out (i.e. I won't listen to a song that's the only good song on a whole album if it's tucked away in storage). I looked into jukebox changers, but they're slow and I still needed to have a way to access music in at least two rooms (my audiophile hifi system upstairs and my 6.1 home theater downstairs). I could probably have gotten an IR retransmitter and ran a cable up through the floor or something. You'd then have to catalog either through the Jukebox machine or a folder what disc has what on it (lengthy process). There'd still be no easy iPod access to such music, etc.
So I then looked into Sonos (expensive with giant remotes and other limited capabilities) and Squeezebox and saw the new Squeezebox which had a remote with a screen display and could use a server system that could also be accessed from PCs (i.e. enable music playback in the den off a computer). So I waited and waited and waited until they finally released the new model and people immediately complained about all kinds of network problems, bugs, etc. and it was obvious the new system had issues. It was also supposedly pretty slow to access information. But I tried loading SqueezeCenter onto both my (non-upgraded) Mac and PC and it was slow as molasses accessing it from the virtual squeezebox software that lets you try the system out before buying a squeezebox (SqueezeCenter itself is free and can be accessed by any internet browsing device including the iPod Touch so theoretically the iPod Touch could be used instead to select music instead of THEIR $300+ remote and send to the Squeezebox. The problem is the newer Squeezebox NEEDS the fancy remote to set it up for the first time. People were trying to hack it so that's not needed but wasn't there at the time (not sure if it is now or not). OR you could order the more expensive previous incarnation that has WiFi and CAN work with the new remote, but can be set up and operated from a traditional IR remote. In any case, it was SLOW as I said. Very unresponsive.
I tried loading up iTunes and loaded a few CDs in it and it looked like a nice interface and I could access everything immediately from the Mac. There was a question about the speed of the controlling software from the iPod Touch, but I figured it couldn't possibly be slower than that Squeezebox system. So I went ahead and bought an iPod Touch and tried the software and Signal was very fast considering how it operates (Remote Buddy was a bit slow, although nowhere near as slow as SqueezeCenter but has since been upgraded and now works reasonably fast, although not quite as fast as Signal). So at that point, I could either upgrade the Mac or I could use a PC to control it. WindowsXP is way less stable and I use it for games, etc. which means I don't want iTunes running and I also use Linux on it is a problem since there is no iTunes for Linux (Rhythmbox can play iTunes libraries but it cannot currently transmit to AirTunes devices, let alone sync an AppleTV; it can sync to iPods, though).
No need to justify that. I'm sure we've all been there. You're not the first one of us to throw away $1000 trying to justify a $260 purchase. I've done it, too. Guilty as charged, don't tell my wife. (Honey, it seemed like a good idea at the time...)
But then I've subsequently come to my senses, and have vowed never to do anything like that again... but that's just me. And from the sounds of the other posts, some other people may be in the same boat.
It's not like I didn't weigh in my options. The iMacs at the time had a weak video card (wouldn't replace my PC for playing games with BootCamp) and would require the sprawling desk expansion and I'd have to throw out my CRT. Mac-Mini has the limits I discussed earlier with slow hard drives, etc., but it would at least let me keep my monitor as the primary display. I could have used a Macbook or MBP, but that would be transportable and not be there all the time to serve the system. So it seemed logical to use an old PowerMac that I could leave running all the time and not have to shut down iTunes on it. But since I bought a new PC last Novemeber, I didn't need a Mac that could run Windows games so my original plan to get a MacPro went out the Window (I got sick of waiting for one with a good graphics card and I waited 6 months last year until November before going ahead with a new PC instead, which I got for $800 that can play all current games). I still wanted to run Mac software, though (non-games), so I figured a faster system would run software well and also speed up the iTunes interface, etc.
The total cost of BOTH systems was STILL less than a new MacPro with only 4 processors and I now have TWO computers that can run almost any application software on their respective platforms and the Mac can play older PPC games (even 3D ones) and the PC can play virtually any PC game out there and I can use two computers to do two entirely different things at the same time (e.g. app on the Mac while playing a game on the PC with only a rotate of the chair to update what's going on with the Mac, etc.) so in a way that's better than running Parallels on a MacPro. I don't need HDTV on my Mac (the PC can do it). I watch movies downstairs on my 93" projection home theater.
I for one think it's pretty cool that you've put that much time and $$ into rebuilding that digital audio. Does it make financial sense to me? No.
I didn't think it made much financial sense buying a MacPro for $2400 when I could upgrade this PowerMac AND get a new PC for $2000.
BTW, Intel Macs are for the most part pretty stable now. It has been a couple of years you know...
Then why do I keep seeing all these Leopard threads about Intel owners have this or that problem with Leopard? Macbooks, MBPs, even MacPro owners have complaints about Leopard. My only complaint about Leopard running on this PPC machine is that its user interface and OpenGL performance takes a significant hit compared to Tiger and that shouldn't have happened. It needs optimized, IMO. Snow Leopard could do that but people seem to believe there will be no PPC support so where does that leave regular Leopard? Slow and unoptimized forever? I've had one unexplained freeze in Leopard while using Firefox3. Other than that, it's pretty solid too, apparently much more so than for SOME Intel owners.