Best computer for usb hi fi source

Between a mac mini, mac laptop, pc tower or pc laptop wich one can be the best sounding usb source for my Hegel hd25 dac?

Thank you!
I like a PC because you have more options. But I buy the separate components, and assemble them myself. Doing it that way allows me to select all parts that I know are high quality. If I had to go with something pre built, I would just get a Mac Mini. You can get good sound from either.
Something silent/fanless if it is going to be in the same room as the system.
Any of them can be made to sound good. However, IMO, Macs are the most natural choice for music. I use a Mac Mini of the series right before this latest release. The caveat with the new mini is you cannot upgrade the RAM. Also, the processors are duo core instead of quad core Intel's.
The MacBook Pro would be my second choice but the IMac is decent too.
I personally use a mini with a quad core I7, 8 GB of RAM and a 516 GB SSD. I also use Pure Music 2 with an outboard drive to store music on. iTunes is strictly a library file using the Apple Remote app with an IPad. Works beautifully, sounds great. Only time things go south is when the home wifi gurgles. Apple's remote comes in handy at those times. You also will need a monitor. Price can dictate which way to go.
My .02 is to buy the cheapest Core i3 or i5, Windows 8.1 laptop you can find. Personally I hear no difference between a cheapo Samsung Book 4 that I picked up at Microcenter for $150 and my Microsoft Surface Pro 3 when either is plugged into my Ayre QB-9 DSD.
Mac mini. I have a dedicated Mac mini in my audio system with no attached disks, 16G of ram, and 1 of the best USB cables hooked to an external dac. My music is stored on a Seagate 5TB NAS central disk that I connect to it thru the wired network. I run my Mac mini headless, you don't need a monitor, keyboard or mouse, I use screen sharing from another mac or from my iPad using parallels. I actually rip my music using XLD from another mac onto the seagate NAS drive (itunes) so I can sync all of my apple devices to this iTunes repository of music. I use audirvana on the audio system Mac mini, I don't use the iTunes interface, I use audirvana's, sounds better but more crude in the interface right now. I use the parallels screen sharing program to interface with audirvana. I also have many TB of disks to perform different types of backups.
As far as ssd, I don't see the need for them. I actually have TB of SSD storage and the way my system is setup everything runs out of memory which is many times faster than SSD.
To me, the Mac still has the edge in industrial design and pride of ownership. That said, I use a PC laptop with an i5 processor, 8 gig of memory, and configure JRiver to play the music files from memory.

Really, for the task of delivering a digital stream to a USB DAC, about the only hardware thing that can interfere is disk drive thrash caused by not having enough memory, and the operating system having to swap things in and out of memory from disk. 8 gig should be more than enough when used as a music server.

However, it's important to optimize Windows to insure bit-perfect, hardware direct transmission to the DAC, and the chosen settings can be DAC dependent. These are normally set through the Windows control panel, but it isn't intuitive, so you either need instructions from someone like JRiver or Google the subject to find step-by-step instructions. The description of JRiver over at has a good tutorial on the issues and options.
I'm not a Mac fan plus they are pricey. Windows 8.1 is awful. I wiped a new Acer laptop, put in a solid state drive and installed Windows 7. All is perfect. Using both JRiver and Foobar but when streaming, media player is easy. Dead silent, tiny footprint, portable and disposable.
04-08-15: Elevick
I'm not a Mac fan plus they are pricey. Windows 8.1 is awful. I wiped a new Acer laptop, put in a solid state drive and installed Windows 7. All is perfect. Using both JRiver and Foobar but when streaming, media player is easy. Dead silent, tiny footprint, portable and disposable."

Download and install a free program called Classic Shell. It turns the Windows 8.1 interface back into the 7 interface. 8.1 does seem to sound a little better, and at least for me, its been much more stable.
If you have the patience to manage Windows - and it can be frustrating..

get a custom PC - fanless, SSD with a linear PSU. You can get a lower power processor and use one of those fanless casings which double up as a heatsink.

Run Windows Server 2012 and JRiver. You can tweak it further - use JPlay and the Windows Server optimiser.

If you don't have the patience to manage Windows, get a Mac Mini from one of those companies that specialise in modifying them and adding a linear PSU. As before, use an SSD

You can JRiver for Mac, or iTunes with Audirvana Plus
You have gotten great replies.

I'd like to add "best" is in the eye of the beholder. For best sound, a server such a Doggiebrowser mentioned (which I use) or a modded Mac Mini. For really best sound you will need to spend a fair amount of time tweaking hardware and software, which in itself defeats the attractiveness and right there it stops being the best option for some. For example, for acoustics you don't want a computer screen in between your speakers, so headless operation is "best" for sound, plus you turn off the video circuits inside the server so there is less electrical noise within, hence allegedly less jitter.

Either Windows based or Mac laptop would be best in terms of simplicity and could get you very good sonics if you are inclined to tweak yhe software piece. Or use the Audiophile Optimizer with a Windows Server 2012 based laptop.

My suggestion is to first decide Mac or Win based on which system you are most comfortable working on today. Either one can provide outstanding sound from what I read (I never owned a Mac server).

Then decide laptop or server. If you haven't been using computers as source I would recommend getting a laptop, even an older one will do OK, and familiarize yourself with computer audio. Some people just don't like it, so better learn this with low investment in time and money. My two cents :-)
I was given a demo of the BlueSound system the other day and IMHO this is the one to get. A proper Linux/ARM based system that looks like it belongs in a B&O showroom.

For complete newbies, you just need to hook up a USB HDD or stream from TIDAL or lossy sources or internet radio.

And if you add a second unit, the OS is smart enough to index all the different HDD attached to the second or third or as many units as you need (up to 34 IIRC).

Or if you are more tech inclined, hook them up to a network drive via SMB.

There's even an Accurate Rip version with a built in HDD to rip yr CDs without a PC.

And not as pricey as a some custom PCs. Designed using tech from NAD - a sister company of BlueSound.

Man, I sound like a fanboy
If you are planning to use this as a dedicated music server, and not as a computer too, then I have found a dedicated server, such as one of the Antipodes units, to both sound better and be easier to operate. They output via USB and my DX unit even includes a non-powered USB output for DACs with internally powered USB inputs.

It rips discs to uncompressed FLAC in about 5 to 8 minutes without any manipulation or programming, automatically loads metadata, and the whole thing operates from an iPad or iPhone using the iPeng app. It also facilitates streaming, back-ups, and copying/uploading files from your network. Look for on-line reviews of several of their units for more info.