When it comes to upgrading power supplies, do they need to pair perfectly with the DACs they are powering, or can you get away with small differences in power requirements?
For example, if your DAC takes a 5V power supply, could you still upgrade it with say…a 9V power supply?
For context, I’m thinking of pairing a new DAC (e.g., Soekris DAC 1321) with my Aune XP2 power supply. The DAC takes 5V and my XP2 is a 9V power supply.
Yes you really want to make sure the voltages match. I’d also make sure it has at least minimum amperage as well, but that can safely be a bit higher than what the unit expects from my experience, but I’d really try to make sure voltages match. Some units might allow for variable voltage by design, but that’s not a majority and it will mark that if it can do it, otherwise I’d really make sure that the voltages match if you don’t want to risk potential damage to a unit
Got it, thanks for the advice! 
Can you think of a company or website that reviews or sells power supplies? I found this site on a quick search, but perhaps there’s a better source.
In terms of reviews you’ll just have to look around, in terms of sells power supplies I can’t think of a specific site dedicated to audio focused psu. That site you linked has a good list of mfg though, I can also think of things like small green computer, uptone audio, ifi, ferrum, teddy pardo, teradak, keces, among others that weren’t mentioned. Personally I’d say keep it reasonable for a psu for a 1321, don’t spend too much because there is a point where you would be better off just buying like a 2541 instead of a 1321 + 6/700 buck psu. I’d say keep it reasonable, personally I’d look for something like a SGC 5V 25W or an ifi elite 5v, or perhaps a fidelizer nikola classic or uptone ultracap if you want to push it.
Yes, that’s right.
If the cost of the power supply is that high, then you can really buy a higher class Dac from the Dac side, which is even Class A instead of Class D.
You don’t have to worry about the power supply anymore.
The only thing you can do on occasion is to buy a better shielded cable up to 80$ that is usually enough and is very much done with it.
And to answer your question about the 5 volt power supply, using a 9 volt power supply probably won’t work.
Because of the ampere output that is still given out.
It would probably only work if you have a 5 volt power supply that outputs 0.5 amps as an example.
And your 9 volt power supply unit outputs 2 amps maximum, then you only load the power supply unit/current requirement with 5 V and 0.5 amps.
I am not an electrician but I would guess that this is how it works.
It does not work the other way round.
In the worst case, ask an electrician who knows.
I would not recommend it.
Firstly, not with such a beautiful Dac and secondly, Class D circuits are relatively sensitive.
The Dacs could react very sensitively to this.
LOL, I didn’t even notice the price of those power supplies from the site I provided. Proof that I should probably get back to work 
Thank you both.
That is likely to blow up the device.
The important aspects when buying a PSU are:
In case you wanted to use that PSU anyway, the below thing is pretty easy to solder together:
