Having returned to base and checked my setup, I’ve spent the last 2 days doing extensive tests on my ND5 XS (Streamer) and the nDAC.
For clarity, my base set up is EPOS 22, NACA 5 cable, Supernait 2 with HI Cap DR attached. The system was warmed up and left on overnight just to ensure all conditions were optimal.
The source for the initial tests was a Naim DVD5.
This fed the Streamer and the nDAC simultaneously with optical cables (identical). Just as a base, the DVD5 was also connected to a 3rd channel on the Supernait 2 (using a Naim 5 pin DIN cable).
Hence the SuperNait 2 was being fed the same source directly and also via 2 D/A converters (the Streamer and the nDAC). The same type of naim din cables were used to connect the 2 converters.
Initially my XP5 XS was not connected to anything (so there was no question of Chassis/floating switches being a contributing factor).
Test 1 was with a variety of known CD material being played by the DVD5.
The A/B test was listening to section of various songs and switching between various channels on the SuperNait 2. I was looking to see if there were any changes in clarity, focus, depth of soundstage, Size/Spread in soundstage, separation between instruments, Bass depth and control.
In just about all of the above categories, there was no perceivable difference between the D/A converters. At a real push, the nDAC may have on occasion had a small increase in vocal presence and a minor degree of extra separation but this was not universal and was a real strain to hear it. It also showed a slightly more forward presentation, a tad more aggressive and was not necessarily as pleasing as the Streamer.
It is worth noting that the 3rd channel on the SuperNait 2 contained the direct feed from the DVD5 using its own converters was slightly inferior to the other 2 feeds. This was mainly due to a very slight reduction in clarify and separation. This feed was certainly very acceptable, and I’d certainly be able to live with this source if I had no other. Given this DVD 5 was bought circa 2005/6, it certainly is/was a great unit for its day.
Test 2
Replaced the DVD5 as source with my Unitiserve again feeding digitally, the 2 DACs. Here I had more access to my usual collection and spent a long time listening across a variety of material.
Again, no real difference detected.
Test 3
Added the XP5 XS to the nDac and made sure the ground/chassis switch was selected on only 1 unit.
No change observed.
Test 4
Swapped the XP5 XS to the Streamer.
No Change detected.
Conclusion
Others may have different mileage if repeating this test, but I conclude that the XP5 XS is a stunning unit and the adding of an nDAC is very (repeat very) much into the marginal gain territory. XP5 XS made no change to my experience. Hence, I will be selling both my nDAC and XP5 XS. That would likely pay for a lifetime Tidal subscription.
I see that there is a NDS available second hand (locally) which I’d like to test-out but I’d only think of acquiring it if I was able to perform such an A/B test to find out the actual improvement, if any.