why expensive streamers

It sounds like what you are describing is a "server", not a "streamer", which often includes a DAC.  If you're expecting a server to vastly improve sound quality, you're correct in your assumption that it will have much less impact than the DAC will.

I went from a Roon Nucleus to a much more expensive server and was frankly somewhat disappointed that there wasn't much difference in sound quality, however there are good reasons to have a good server (which I consider the Nucleus to be) - onboard SSD storage, Roon compatibility, better connections to the DAC among them.  

In my case, the server I have also includes a top notch CD player that reads the CD into a buffer on the streamer, upsamples it, and sends it to my DAC.  It also has i2s connectivity and the two pieces are from the same manufacturer and designed to play well together.  One of my previous DACs was not ROON ready, but connecting it to the server allowed ROON to "see" it.

My opinion / experience is that for most people an expensive server will have little if any impact on sound quality, but may offer other benefits.

I'm using an ASUS ROG gaming PC as my streamer running Windows 7. I stream from Qobuz. I also have over 4,000 CDs which is my source most of the time. I run USB from the ASUS to my Berkeley Audio Alpha USB which is hooked up to my Berkeley Alpha Reference II MQA DAC using a BNC cable. My CD transport is a Jay's Audio CD3 Mk III.

I have compared the streamed Qobuz file with its corresponding CD (being careful that they are the same version) for at least 20 titles. The streamed file sounds identical to CD in every case.

I simply would not expect the streamed file to sound better than the CD played through the same DAC. If it did then I would question the quality of my CD gear. If my PC is somehow adding noise or corrupting the file then I can't hear it. I don't understand how a multi-thousand dollar streamer is going to sound better than a CD played through a Jay's Audio CD3 Mk III.

BTW, I have ripped my CDs to uncompressed FLAC using dB Poweramp, and I have compared these files to the CD. They sound identical.

I'm baffled why more listeners don't do this simple test, assuming they have CDs to compare with. IMO this should be the most important criteria for a streamer. Does it sound as good as the corresponding CD? If the streamer sounds better than the actual CD then I would propose that something in their system is awry. It's extremely hard to understand how a WAV file can be chopped up into packets, sent through thousands of miles of wire and hundreds of switches, go through your $200 home router, then reassembled into a file that can be read by a DAC, and actually sound better than the WAV file read from a CD.

Having said all that, my next purchase is going to be an Eversolo DMP-8 streamer but I'm getting it mostly for convenience. The reviews indicate that it has a very good interface and it has the ability to have enough memory installed so that I can put my ripped CD collection in the streamer which will avoid having to get a NAS or server.

My advice is to use CD playback as a standard for comparison. This is the only way to genuinely compare the sound of streamers IMO.

I don't know why one streamer subjectively sounds better than another. From the reading & internet research I've done they should all transport the signal the same way. Bits are bits as "they" say. From personal experience, & that doesn't include $10k plus streamers, there definitely is a perception that certain ones sound better/worse/different than others. As ridiculous as this will sound I almost feel like nothing about digital streaming is just cut n dry, all the same, or an exact science. 

I've tried to tell myself it's just some sort of bias, or psycho acoustic tricks my brain is playing with me..but normally if that is the case one can just give it a little time & reality will eventually settle in. Certain switches, digital cables, power supply's, isolation, all seem to have an effect on digital signals. 

I understand science says differently with some of those things. And as much as I want to believe or tell myself that all transports should sound the same..my perceptions are too strong & obvious to overlook. I wholeheartedly feel that their are levels to these streamers & how the sound or perform. Now are these differences worth the premium cost of some streamers? That is for the buyer to decide. 

@glennewdick 

Have you tried RemotePC?  It's included with Windows or as an app on android.  I use it and run my PC from both my laptop or my tablet.

If you'd like to PM me about the changes you made to your PC I'd like to learn about it.

@8th-note

I simply would not expect the streamed file to sound better than the CD played through the same DAC. If it did then I would question the quality of my CD gear. If my PC is somehow adding noise or corrupting the file then I can’t hear it. I don’t understand how a multi-thousand dollar streamer is going to sound better than a CD played through a Jay’s Audio CD3 Mk III.

You certainly do not need a multi-thousand-dollar music server/streamer that uses a lot of costly parts (and markup) to eliminate noise from getting to the DAC. A simple test would be to use a Sonore OpticalRendu streamer (used for about $700) with fibre coming out of a $100 (or less) network switch. Input the fibre to the Rendu and then USB into your DAC from the Rendu. Compare that to the PC going direct to your DAC via USB. If you cannot hear a difference, then you are set. I hear a huge difference.

Another factor is the ambient noise of a computer near an audio system. I have a computer in my office that is next to my office system. That PC is a SIlentPC and cost $6k to make it silent, but I do not put my ROON Core on it. I could but I want a PC that I have running for most of the day for my ROON Core.

For that I have a very internally noisy $500 computer nowhere near my audio systems (under a bed in the guest room). My systems are in the Livingroom and office. I use the "low-cost" OpticalRendu to stream. The Rendu’s use fibre optic cable just before the DAC. That is import because fibre is made of GLASS and cannot carry the analog noise in the computer network (or USB into the DAC (for the most part)). The same noise that you can spend a fortune to eliminate with a dedicated music server.

BTW - the chances of CD sounding worse than a streamer are rather low. CD has a big advantage in delivering the bits and could sound better. Spending a fortune also on a Transport seems questionable to me when buffering should render the need for a Transport less important. That Aurelic S1 non-fibre streamer ($1999) with buffering CD playback seems like a killer feature.