Sorry it might not have been clear. If you want isolation you need to feed fiber optic ethernet to Marix 3.
The Matrix 3 also has USB input for digital source . If you power Matrix 3 with a computer’s 5 volts or wall wart SMPS by USB you defeat isolation. Isuppose if you have quality LPS that offers USB power that would work.
I’ve just preordered X-Spdif 3! About 3 weeks to wait. Will post my findings after my unit will be at home and tested…
The specs say external power is 12v DC but the fine print says external PSU should not exceed 12v. I wonder if this means it will run on lower voltages like the prior model and they just neglected to specify a voltage range as they had for the X-SPDIF2.
does the matrix 3 benefit from an external power supply or not? I have a matrix 2 and LPS so interested if the new one performs same or better with USB power from streamer.
Forgive the ignorant question but if I’m using an Innuos via USB to the new Matrix 3 would the system benefit from an LPS? Not sure what an LPS with USB power is and I assume the USB from the Innuos carries 5V with it.
Yes the matrix will use the LPS power in priority over USB 5V for power. The SPDIF 2 sounds better on a LPS so I bet the 3 does also.
Buy one and inform us please.
I would but I have 2 issues 1. I am in the UK and dont see the Matrix 3 at a dealer yet and 2. I would need to buy a 12V LPS since mine maxes out at 9V (uptone). so I will eagerly await others findings. personally I would love to know it performs well with USB power so I could sell my matrix 2/lps combo to fund the purchase of a 3
It is a pretty new piece. You might be even more successful asking passerby’s on the street if they know. And if you have an Uptone power supply I think you can select different voltages. The important point is it can be powered off the incoming USB for no extra outlay of cash. And it will sound fine that way.
That is debatable because the noise on the 5v rail can vary from source to source. I did a test with the USB on my late model Dell PC and my Aurender music server using an external 5v LPS and there was no difference with the Aurender compared to the PC. Obviously Aurender did a better job cleaning up the rail and this supports the many claims in this forum how the Matric works for some but not others.
BTW, I posted screen shots of my spectrum analyzer running through test on my LPS and inserting a DC blocking capacitor into the chain.
I don’t know how matrix3 will handle it, but I am quite sure that current matrix uses external power only for Output interfaces, the USB interface (and recloker etc) is still powered via USB , if there is power present.
I found this empirically with the help of Y-split USB cable - when I left the power leg disconnected , Matrix still worked , but the sound was quite a lot worse than when having power on USB present (either from streamer , or even better good LPS).
I ordered a -3 from Power Holding and it was shipped today. I intend to swap it for a -2 between a Roon-dedicated NUC 10i5 and a DS Sr, whilst installing the older Matrix between a pc and the dac.Arthur Power advised that mine was the first US purchase of the new version.
Cannot wait to learn your experience!
When you connect an external power supply it automatically disconnects the USB power bus but allows devices like mobile phones to connect that do not support power output
This may not be necessary. As was posted above, it may be a misinterpretation of the specs. The specs for the ‘2’ recommended 12V as a maximum. I think it’s reasonable that this also applies to the ‘3’. Why don’t you contact Matrix Audio and put the question to them on our behalf? 
Once again incorrect. The typical voltage for an FPGA is 1.3v to to 3.3. Matrix specifically warns about not connecting an external LPS greater than 6v to 9v
“Note: Don’t connect to the power supply with a voltage above 9V, or will cause
damage” (taken directly from Matrix)
My bad. I stand corrected. 
I think it’s still worth clarification from Matrix Audio what is the operational voltage range.
It’s published in the manual Mike. In FPGA products in general, a variety of stages with higher voltages can connect to the FPGA but they always get regulated down first. These stages may or may not exist with the Matrix.
Yes about the operation voltage. My Aurender works fine with the 5v rail into the Matrix and no external LPS. However, the manual says 6v - 9v for the LPS. I have mine connected because I have not got around to removing it. It is adjustable from 4.5v to 6.3v which is where I have it right now, 6.3v
Yes I have an X-SPDIF 2 of my own and have often referred to the manual. I’m well aware of the recommended voltage range of an external PS for it.
The context of the original comment was for the X-SPDIF 3 and whether or not our current (fixed) voltage LPSs we use for the ‘2’ can still work with the ‘3’. The ‘3’ manual specifies 12V for an external PS and recommends not to exceed 12V but it doesn’t indicate a minimum for the external PS. That’s what I think is worth clarification from Matrix Audio.
You are fortunate to have an LPU if you decide to upgrade your Matrix. I’m a bit dumfounded how some ‘audiophiles’ are mislead first not knowing if they in fact need a Matrix or not, and why the rush to buy an overpriced LPU at 12v because someone told them to. There a better and less expensive LSUs besides the Farad which likely just another overpriced piece of gear out of the Netherlands. I wonder if it rolls of an assemble like in some Chinese SH factory.
Mike, what’s your USB source? Have you taken your Matrix out of the chain just for comparison?
My common sense tells me the Matrix 3 will not justify the extra expense when there are other areas that can make a more noticeable improvement to a system.