Power supply differences are again largely mythical unless you are seeing power supply spuriae in the audio bandwidth and at levels within the dynamic range of the system. If your system has a peak SPL of, say, 113 dB, that requires a 90dB sensitive speaker and 200W of amp. If the noise level in your home is 50dB, that gives you a system dynamic range of 113-50 = 63dB. If the noise from your DAC is -100dB, improving to -110 dB is "measurable, not meaningful" because that noise is already so far below the noise floor of your system. Just like if wearing a certain type of shoe sole reduces your chances of being struck by lightning by 50%, no rational person is going to throw out all their other shoes. The improvement is measurable, not meaningful.
@panzrwagn I appreciate your technical contributions and insights on this thread. I’d like to suggest that there are at least two ways that power supplies can affect the sound of a component in a playback system.
One is the possibility of having a direct effect on the performance of the component itself, either by cleaning up the power to the component from the wall, distributor, power conditioner or supply cable, or, by doing a better job converting voltage and current from the wall to the specifications required by the individual component. Both of these possibilities could result in less noise reaching the component and/or the appropriate deliver of current as needed for the unit to function at maximum performance.
A second possibility is that a power supply for a specific component is interacting with your entire system, either through the supply cable(s), or by producing noise that is fed directly back into the wall/distributor/conditioner in ways that degrade the performance of your other components and ultimately the overall performance of the sound you are getting.
Any power supply, whether built into a piece of gear or external is a de facto part of your overall system performance, and along with the supplying power cord, a possible source of noise to adjoining and connected components. Because of this there may be value in trying different power supplies in your system to determine if there is a positive effect. And because of these possible interactions and the fact that your cable loom is it’s own “system” affected by adjoining cables and any electrical fields generated by the adjacent electronics, experimenting with different power supply cables for aftermarket linear power supplies can be helpful, or not, depending on your particular combination and configuration of components on your shelf.
Modern Electronic manufacturers, especially from Europe, are looking for ways to reduce the energy draw of the gear they sell. SMPS are excellent for producing specific current and voltages efficiently with little heat loss. They may not be the best solution for high end hifi systems where you could end up with multiple switching supplies connected to the same power distributor. I have banished all wall warts from my system and even removed an internal switching supply from my streamer. My system sounds good to me, but my monthly electrical bill is higher.
YMMV
kn