DAC connection to computer

@rbstehno stand alone DAC is my preference also since it isolates the conversion from both the computer's and the amp's electronics but OP is asking specifically about connecting his PC to the DAC in his integrated amp.

Ah.

"A streamer is a computer."

A single use box is totally different than a general use PC.

Galvanized, fiber optics, sales gimmicks.

+1 @travelinjack 

In addition to Foobar, you have the JRiver Mediacenter as another option for locally stored music. Connection from your computer to the Mac 7900 via USB A/B.

Using (for example) Quobuz as the source of music (PC app available), you can send the stream via USB to your DAC as well.

Give it a try. If you are satisfied with the soundquality, you will not need any additional hardware. If not, you may want to go with a dedicated streamer.

I am using an Android platform including USB Audio Player Pro going directly into the integrated amp via USB A/B (and as well via separate DAC to the amp).

It is all about personal preference.

Others have said it, but it is probably useful to summarize:

1) PCs are acceptable sources. Sonically the biggest issue with them is that they are not optimized for audio play back. They have inadequate DAC chips, they are prone to digital timing errors, capacitors are low grade, are prone to noise interference from the other functions of the computer, and other issues.
2) You need some sort of software program to manage music. Paid streaming services such as Tidal provide this. If you have music stored on a hard drive that you wish to play you need a program for that. Room is one service that helps you manage both in one space.

3) The OP has a DAC in his integrated amp and it surely will best the one in his computer. He therefore just needs to send the digital stream of the PC to the amp. The most common way to this is usb. Presumably the DAC in the amp offers other digital inputs but most computers tend to offer just usb as a digital output so his computer will probably be the limiting factor.

4) What is a streamer and should the OP buy one? Streamers are basically networking computers that have been optimized for sound. Some contain DACs. They also look like audio components.

The OP is obviously new to streaming. I am not familiar with his amp. McIntosh is a storied company. I can’t imagine that it would sound bad. Start there and stream from your computer. You may be so happy that you never feel the need to move on.

I used a computer into a DAC for several years before buying my first dedicated streamer. You can always upgrade later but since the OP already owns the amp and a computer it would be logical to start there

Travelinjack-I agree with you but some of the other posters are way off base. 
My server running Roon will never be hooked up to a dac. When I was using this Mac straight into the dac, the server was in another room and I used Ethernet to the dac.

All the Auralic/aurender server/streamers are computers, no ifs and buts about it. They run a proprietary version of some hacked Linux OS, big deal. I’ve done this before running Linux on a commercial server with commercial solid state technology (again using Ethernet to the dac) and there was no benefit to sound quality. IMO, the only benefit you will see is if the server/streamer claims they have an audio usb port, which some drool over. Me, I’ll never use it. You can buy thousands of $$$ of usb gimmicks/tweaks and it will still be flawed.

Who cares if a new Mac is running another task in the background. The new Mx processors run 38 trillion ops, so I don’t think it will slow down any. But, I turn off everything that is not needed during my listening sssions, after that I run my backups, etc.

You take a Nucleus that the vendor removed all diagnostic commands from the OS thinking that it will improve the sound. If it was running on 30 year old gear, that would be the right thinking, but not running anything in the past 10 years. Now nobody can figure out what is wrong with their nucleus, they can only guess which usually leads them to buying new hardware which might not be the problem.