Actually, DON'T use just any "walwart adapter" You can get noise and/or damage the pedals because not every adapter is designed to use with pedals. It MUST be one designed to use with pedals.
While I agree that people need to be very careful which supply they use, the problem is
not whether the wall wart is designed for use with pedals. Any supply "designed for pedals" may end up with noise, if the pedal chain has incompatible grounds. And damage will only occur if the supply is
unregulated. Even some supplies meant for pedals are unregulated, like the old Boss ACA. So people need to be aware of regulated vs unregulated, not whether it's "for pedals"; and they need to know that
noise is usually not caused by the power supply, but by the pedal chain (of which the power supply is one part).
A note about isolated outputs. Contrary to what you'll read on the internet, there are only 2 reasons you need isolated outputs.
This is a good example of why people should not trust everything they read on the internet. Your examples are both false.
1) You happen to have a pedal that has Germainium transistors. I won't get into the technical, but if you daisy chained a silicon transistor pedal (nearly all) with a Germainium pedal the 1Spot would see it as a short and turn off. Unplug the Germainium and it will turn on. Plug the 1Spot into the Germaium ALONE and it will run it. (You CAN daisy chain 2 or more Germainium pedals).
As Boomer already explained, you are confusing "germanium vs silicon" with "PNP vs NPN". Totally different problem, though voodoo thinking could lead you there if one time you connected a germanium NPN with a silicon PNP, for example.
2) You have a pedal with bad power filtering. WHen you chain through power the pedals become electrically connected. If the pedal doesn't have to power filtered properly it can leak audible noise in to the power. These pedals are few and far between because proper filtering is common and costs about $0.02 per pedal. It's easy.
Again, voodoo thinking. While it's true that the audio path can be filtered and protected from leakage from the ground path, it is not so easy, not just a matter of adding a few cents of components. For example the traces on the board may be too close together, or a bit of solder or a tin whisker may make a tiny bridge, not big enough to be the path of least resistance, but enough to leak. But even this doesn't address the problem of ground potentials that I described before, which are the actual cause of the noise.
Isolated outlets DO address the root cause of the noise, by preventing a feedback loop for the ground potentials. And THAT is why they matter, when noise problems crop up.
what are your opinions about 1 Spot giving off noise though? there seems to be a fair amount of people who think that the 1 Spot gives off a hiss and something like the Voodoo Labs is more quiet. i mean, just look at this:
Again, the 1Spot is not giving off hiss, and the Voodoo Labs is not quiet. They are not the source of the noise! It's easy to think that way though, since the noise may appear and disappear when you change power supplies. The truth is that the supplies are only a part of a complex set of interactions between all your pedals, and that set of interactions is the actual source of the noise.
Edit: There are cases where a power supply can be the noise source; for example in some situations you can hear the clock noise of a "digital" switch-mode supply. But even then, the only reason the clock noise is audible is because of an incompatibility along the ground planes of the system.
