Strangely enough, I've been seriously re-thinking sources, and their relative importance, for my DAVE.
With a start point of my elderly Nagra CDC (very pricey integrated CD Player/pre-amp) -> Optical cable to DAVE.
If this is the reference point, then in approximate chronological order of change over the year...
- Replaced CD player with Windows 10 laptop, Redbook FLAC on internal SSD, running off internal battery, app player=JRMC, all DSP off -> TA Black Diamond USB cable -> DAVE
- This sounded different, but broadly equal to reference, the latter still overall slightly preferable in an analoguey kinda way
- Same laptop but with JRMC replaced by HQ Player, all DSP off apart from Dither
- Now clearly better than reference, albeit still in same ballpark SQ. This was the point when I knew my trusty old CDC's days were numbered
- Insert microRendu with low cost iFi p/s, an old Linksys WiFi router with stock p/s, Monoprice Cat 6 ethernet, laptop connected wirelessly
- A step change improvement in SQ. Like upgrading a main component. This was the point of no return.
- Replace iFi p/s with MCRU linear p/s, all stock bar upgraded DC power cable to a (rather thin) 1ft silver cable. (MCRU is a UK two-box p/s Price around £240 + around £50 silver DC cable)
- Worthwhile further improvement
- Replace Monoprice ethernet cable with Supra CAT8
- Worthwhile further improvement and staggering VFM at £35 [1]
- Replace laptop wifi to router with my now spare Monoprice ethernet cable
- A backwards step. Yes, I was surprised too. So the WiFi stays for now [1]. Maybe a better ethernet cable would have turned the tables?
- Replace MCRU p/s with LPS-1 with stock DC power cable
- Worthwhile further improvement. Possibly a step change, but can't quantify this because the next few steps came in quick succession, so blurred the significance of the original change
- Replace LPS-1's stock DC cable with a short 4 inch silver wire - cut from my now spare MCRU, I soldered the cut wire to a couple of Oyaide DC plugs
- Worthwhile further improvement - despite my dodgy soldering skills
- Replace the Router's stock p/s with my now spare MCRU
- Something interesting happened here that I couldn't quite quantify. Was this a step "improvement" or a step "difference"? Led me to quickly try:
- Raided my box of spares to dig out: an ancient Transparent near-entry-level power cord; AMR and HFT Supreme Fuses; HRS damping plate and footer. With a combined result of...
- Router with fully loaded MCRU was a step improvement. Chose the HFT over AMR fuse, and both were directional (in an AC circuit! Yes, really). [1] [2] [3]
The end result was: Laptop ->wifi -> router with fully loaded MCRU p/s -> Supra ethernet cable -> mR with LPS-1 p/s with silver DC cable -> TQ USB cable -> DAVE
Despite the insertion of several boxes/cables into the digital signal chain, this was so far ahead of my reference point, I wouldn't have believed it had anyone told me a year ago. As always, YMMV and these changes are probably objectively very small. None of them, apart from [2], directly changed the tonal signature of my system, although many of them indirectly influenced tonal perception by removing some hash and grain, and increasing focus. The conclusion for me is that just about everything upstream of DAVE can matter. This goes against some earlier posts where theoretically DAVE+mR should be largely immunne to upstream quality. But my usual quip applies here: I have no option but to trust my own ears.... becuase they're the only ones I've got.
Notes:
[1] These are all candidates for my "I didn't see that one coming" award for 2016. The winner though was the last change: fully loading the MCRU p/s for my router, as it simply gave me my most musically satisfying "I didn't see that one coming" moment of the year.
[2] The HRS damping plate on the MCRU (as well as on DAVE itself] slightly increased the bass, and seemed to add "weight" to the whole sound stage, both of which were very welcome for my Stax 009's. It seemed to affect other parts of the frequency response as well, but I couldn't immediately get a handle on what that was exactly. The HRS footer helped the MCRU, but didn't do anything to DAVE, so obviously YMMV for the hundredth time.
[3] Would I have heard such a difference in the last change if this instead been the first change to try? Do some of the later changes negate the values of the earlier ones? Dunno, as I don't have the patience to try all combinations. But I'm sure that issues in one part of the chain can mask the effect of other parts.
Next thing to try:
The SOtM something 200 rival to mR, which some early reports reckon is better than mR and costs less.
And maybe the SOtM ehernet cable, as romaz liked above all others
And Roon once I get a better broadband connection to my house.
Not in a great rush for these, just going to enjoy what I currently have and rediscover my music collection all over again..
Thanks for the info ^^ i will check around to get them for a good deal. 
