Do streamers make a difference?

I also use Roon with various streaming sources.  Each can and often does sound quite a bit different.  DAC used in each case is probably the biggest factor, though two different sources to same DAC may sound different as well, but generally less so.  An example is ASIO versus WASAPI source on the same PC sound similarly good via asynchronous USB connection to DAC, but still very subtly different.

Roon core/server used has little or no impact on sound.  The main thing there is that the computing engine is powerful enough to run Roon efficiently and reliably and that network connections have sufficient bandwidth.  I find 2g wifi is sufficient if set up properly in a manner that ensures a strong connection using either mesh or wifi extenders.  Roon does recommend a wired network connection between core/server and router, which is best but I find not an absolute requirement.

I can easily recommend this latest gen Asus NUC PC (cost:  ~  $1K) to run Roon core both efficiently and reliably:

Intel® Core™ 7 processor 240H

Processor    Intel(R) Core(TM) 7 240H (2.50 GHz)
Installed RAM    16.0 GB (15.5 GB usable)
System type    64-bit operating system, x64-based processor

“Nagra and Playback Designs share design technology and the Nagra Streamer connects to the MPD-8 with the same proprietary fiberoptic connection as the USB-X4 and also incorporates the identical clock, yielding the same sonic benefits in terms of noise and jitter reduction.”
@tcutter 

This is the X-factor in retrieving the optimal performance from your Nagra streamer. When I first looked at Nagra, I knew N-Link would be essential to unlocking the streamer’s full potential. And LPS would be the next logical step! 

Congrats! 

Playback Designs also has a streamer, the MPS – X. It’s role is similar to the Nagra in terms of accepting an ethernet stream and then converting it to an optical format. It is roughly $6000 more and for that you get perhaps a different streamer circuit, but also a great deal more connectivity, including coax, AES, fiberoptic and Toslink in;  AES, coax, fiberoptic and USB out. A first class power supply is also included in the price. While I’m sure both are very good streamers, I think the main benefits are the galvanic isolation and jitter reduction that they both provide. The DAC is presented with the best signal possible. 

I am a big believer in everything matters, and Roon core machines and Streamers are no exception.  Most salient points have been covered here, especially how USB connections mean the DAC handles the clocking and AES means the streamer handles the clocking.  

I am a fan of a machine that is both Core and Streamer.  To me , this puts core directly connected to the streamer, and special connections or optical isolation are not needed between the two.  Additionally, it saves a component, space, power cable and connecting cable.

I have two such machines.  The oldest, a Grimm MU1, can handle both Core and streaming elegantly.  It outputs AES and not USB, and works beautifully with my Mola Mola Tambaqui.  It formerly handled core for my main system as well, using an Auralic Aries.  This is now in my second system, and Roon Core function has been replaced by the Pink Faun Scion, which runs core and streams USB to my Master Fidelity Nadac C and D (clock and DAC).  As such I have disabled the Roon core function of my Grimm and use it as streamer only to the Tambaqui.  This system now sounds better with the Scion running Core, so my findings differ with thoughts that core machines don't affect sound.

I have appreciated the sound improvements of every streamer upgrade I have made.  Digital glare decreases and music is more relaxed and spacious.  Listener fatigue decreases.

I also have improved my sound with stacked audiophile switches, and prefer this way to optical isolation.

As to the thought by @lanx0003,

I believe there’s a point of diminishing returns, and I haven’t yet determined where that price point lies.

I can't argue against that, but improvements are still to be had at every level.

Congrats on a nice system @tcutter!

Streamers make a difference in my experience.  I upgraded from a Blusound Node N130 in my main system to an Innuos Zen MK3 and I noticed a difference in streaming music with my Holo Audio Cyan 2 DAC.  The source matters in a high end system.