| Adjustable PSU
The three rails on my PSU are adjustable via the on-board trimmers.
Switching* PSUs are noisier than Linear PSUs. So not unless you really, really need it to be a switching type, Linear PSUs are preferable.
* If you need boost/buck/buck-boost functionality in your PSU, or very high wattage and efficiency, then switching PSUs are the only solutions. But EMI/RFI from the Switching PSU inductors can find it's way to your mic input circuitry and can be heard as "hashing", "white noise", "whining" sound.
Note that line regulation and ripple of switching PSUs can match that of Linear PSUs, but Linear PSUs are generally quieter because they don't have any switching transients that can generate RFI/EMI.
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