Mono and Stereo review of the 18NS Dart Pre by Matij Isak

[Zeotrope]

if i had to guess as to the reason for this; it's likely related to grounding in one way or another....and is not power supply related. since i always run my 18NS in battery mode. and maybe it's just grounding the separate charging box and that a better power cord matters for that.

i do have my Tripoint Elite ground box grounded to my 18NS (at the phono ground post) with a Thor grounding cable.

Mike, have you experimented with other ground locations on the 18NS? I believe the phono boards are completely decoupled from the preamp circuit when not selected, so grounding at the phono board won’t make a difference on other inputs.

 

[morricab]

i did not want it to be so, as it did cost me money to know it. but as the preamp is the pivot point for everything, i had to do it.

So a power cord sounds better hooked up than disconnected on your battery powered preamp?

 

[Zeotrope]

So a power cord sounds better hooked up than disconnected on your battery powered preamp?

Not sure what the point of your post is? Mike clearly said it does. I suspect he's correct and that it's due to grounding. I'm looking at grounding options, specifically the new Shunyata Altaira, but I don't think that grounding at the phono ground terminal will work for for non-phono inputs, since the phono board is not in the signal path when not selected.

 

[Zeotrope]

if i had to guess as to the reason for this; it's likely related to grounding in one way or another....and is not power supply related. since i always run my 18NS in battery mode. and maybe it's just grounding the separate charging box and that a better power cord matters for that.

i do have my Tripoint Elite ground box grounded to my 18NS (at the phono ground post) with a Thor grounding cable.

Mike, I would try removing the ground from the 18NS. I just tried grounding the phono input to my Shunyata Denali V2’s built in grounding system and the noise floor increased! I think this is because the 18NS is not connected to the AC mains unless the battery is charging. So by grounding it, you are now adding some noise, since the ground plane noise is not zero.

 

[Zeotrope]

I just wired a ground wire (for now, 16AWG Duelund tinned copper) from a chassis screw on the 18NS power supply to the Denali 6000 v/2 ground terminal.
Results? Too early to tell but the noise floor did appear to drop slightly. It certainly didn’t increase as it did when I connected the ground wire to the Phono input ground (which doesn’t make much sense, at least in my humble opinion, for the reasons above).
Use this screw specifically- not all case screws on the PSU are tied to ground!

 

[Zeotrope]

Now grounded with a proper Shunyata Omega ground wire into an ALTAIRA Signal hub:

 

[dandylinpsst]

Now grounded with a proper Shunyata Omega ground wire into an ALTAIRA Signal hub:
View attachment 101026

If you want to be grounded the 18NS power supply, try this place case screws(outside).

 

[Zeotrope]

Thanks for the internal photos. The screw that I used has more room to connect a spade type connector for the ground wire.

Do you think the power supply is electrically connected to the preamp when the battery is powering it? DartZeel says no, I think; but there are reports that the AC makes a difference to sound quality, which shouldn’t be the case if the power supply is completely disconnected when running on battery power.