Possible problems with linear power supply P50

[NIoSaT]

Hello,
long time lurker here

I am thinking about buying a P50 for my, soon to be, topping 50s stack (D50s+A50s). Not for the audio benefits (I have read Amirms post) but for the added convenience.
Currently I own a D50s and a Schiit Magni3 while waiting for the release (and measurements ) of the A50s.
At the moment I am running my D50s form an old usb-charger and the Magni from the included power brick. All plugged into the same extension cable as my PC, Display and some other "wall-wart" power supplies.
I plan to power my D50s and A50s with the P50. While the P50 will be powered from the same extension cable as before.

I know there probably won't be any audible benefits with the P50 but my question is, could I accidentally make it worse?
Could I create new problems by using this setup?
As far as I understand the DAC, AMP and everything else on the extension cable will be grounded together.

And the comment from JohnYang1997 here

Now it's a complicated issue. The p50 grounds the output ground to earth. So i don't recommend using it without being conscious about the grounding of your signal chain.

makes it sound like I could mess up several things.


TL;DR:
A topping P50 probably won't improve my audio but can it make it worse?

 

[Atanasi]

If P50 makes a ground connection, it may add a ground loop. A50 and D50 wouldn't even have balanced interconnections to rectify this.

 

[ripvw]

I used the D50s/P50 combo for a year - no problems. I've since given it to my niece who is also using it everyday without issue. To help prevent ground loops without the benefit of balanced XLR connections I suggest plugging the P50 into the same outlet as your source(s), A50s (I used both the JDS Labs Atom & the Schitt Heresy successfully), along with your amp or powered speakers. Also, you can use these RCA/XLR cables from Benchmark to run from your A50s to your amp or powered speakers if they have XLR inputs available.

https://benchmarkmedia.com/collections/all-products/products/benchmark-rca-to-xlrm-adapter-cable

One of the benefits of the P50 is that your D50s is always powered up and that seems to help when recovering from a OS upgrade or computer crash - my Mac always found the D50 upon the completion of an upgrade or reboot. When I ran a different DAC using power from the Mac USB the system did not always recognize it after the event and I had to go and manually choose the DAC.

 

[digitalfrost]

The D50s has a barrel plug, i.e. 2pin connection with no dedicated ground connection (Class II device https://en.wikipedia.org/wiki/Appliance_classes#Class_II).

From my understanding it should not matter where the power the Class II device comes from, it has no connection to ground so it cannot form a ground loop.

Your amplifier also has 2pin plug only, as does the A50.

I think it'll be fine. That said. The P50 is expensive and probably unnecessary. I run 2 Topping D50 from a 2A USB charger...

 

[Atanasi]

Also, you can use these RCA/XLR cables from Benchmark to run from your A50s to your amp or powered speakers if they have XLR inputs available.

Would it make sense to drive powered speakers through the balanced headphone output, using a 2.5/4.4mm to 2 XLRs adapter? This way, one would get a balanced source.

 

[AnalogSteph]

The D50s has a barrel plug, i.e. 2pin connection with no dedicated ground connection (Class II device https://en.wikipedia.org/wiki/Appliance_classes#Class_II).



From my understanding it should not matter where the power the Class II device comes from, it has no connection to ground so it cannot form a ground loop.

You have to look at the mains power plug on the power supply, not the secondary-side +5V/ground connection! You could have a connection from mains PE to power supply ground and from there to DAC ground.

Looks like the P50 is IEC Class I if @JohnYang1997 himself says so.

In a lot of scenarios there should be no (more) issues with this, like when using the D50s on a regular PC via USB (doesn't look like it has a USB isolator). A ground loop mostly running across the PE conductor of the P50 is still likely to be less problematic than the same for the PC's plus USB shield.

About the only case where things would get worse is when you're using Toslink input because you needed the galvanic isolation.

 

[NIoSaT]

Thanks for the answers!
So it should not make any new problems, running amp and dac from the same power supply.
The usb input from the PC is not changed by that.

I still might consider a P50, just for the "neat" package, even if it doesn't give me any audible benefits. Although it's kinda expensive just for being "neat".