Responses from yage

Ethernet cables
1. Yes Cat8 is the highest rated cabling but guess what - Gigabit Ethernet has been around for a long time (~1998) and only in 2027 is it projected to overtake 100 Mbps. See https://www.lightwaveonline.com/home/article/14302651/gigabit-ethernet-se... 
Ethernet cables
@audphile1 How is Cat 6A obsolete? Seeing as how streamers that cost thousands of dollars already use obsolete processors and gigabit Ethernet, I think most audiophiles will be ok.  
What makes One Music Server Sound Better than Another?
The point of this thread is to ask, how come I perceive the the DejaVu server as sounding better than the Antipdes DX? Were you doing sighted listening tests?  
Ethernet cables
I suggest the Blue Jeans Cat 5e (Belden 1700A) patch cable - https://www.bluejeanscable.com/store/data-cables/index.htm. Proven performance as every cable is tested before it ships to make sure it's within spec (you're given the test printout in t... 
DAC Output Splitter
In that case I would look for a SPDIF switcher like the following:   https://inday.com/da4x.html https://www.cs1.net/products/cable_solutions/DAS-001.htm    
DAC Output Splitter
Does your streamer not output via USB?  
Integrateds: Luxman vs. Ayre?
Ayre DACs can certainly be endgame. I wouldn't be worried about that.   The nice thing about the EX-8 is that it has a pass-through mode which sets the amp to unity gain. A good feature to have since you're integrating it with the MRX540.   No... 
Tidal FLAC vs. Qobuz
Yeah - most likely they are. If you don't want to use two apps for music playback, then I guess you're stuck with MQA rather than pure PCM. Otherwise, there's no reason to panic since the Vault supports TIDAL Connect.  
Tidal FLAC vs. Qobuz
@mojo771  After doing some more reading, I think @moonwatcher is most likely correct - the app acts only as a remote control when TIDAL Connect is used. This means that the audio data is sent directly to the Vault over your wired network connecti... 
Tidal FLAC vs. Qobuz
@mojo771  Are you sure it's sending the audio data via Bluetooth? If you're using TIDAL Connect with the Vault, then it's using Wi-Fi not Bluetooth.  
Preamp headphone amplifier
I glanced over the specs on your ML pre and it looks like the headphone section is fairly well designed so it’s not surprising that you’re getting good results. Hope you enjoy the tube amp. I’ve also found Donald North’s designs to be truly excep... 
Receiver ohms?
Ideally, you want a headphone output with the lowest output impedance possible and definitely lower than the nominal impedance of your headphones. Otherwise the frequency response will be modified by the impedance curve of your headphones (among o... 
stationary USB DAC vs portable all-in-1 DSD player - range of quality difference?
Personally, I don’t like DAPs because it’s just another gadget to maintain.   Instead, I use a E1DA 9038D6K (link) with my Android phone and USB Audio Player Pro. It supports 24 / 384k PCM and DSD256. Basically reference quality performance in a... 
Class A, A/B vs Class D amp Soundstage
I'd check the wiring between your speakers and amp - sounds like you may have wired one speaker out of phase (flipped + / -).  
Do I Need a Dedicated Streamer?
@caslon  Do you have separate 2.4 GHz and 5 GHz Wi-Fi networks set up on your wireless router? Sometimes connection problems between two devices can happen when they're roaming between the two frequency bands.