SUPER LONG POST! (Like this one
)
So I will respond to a bit what I definitely agree upon.
Some topics to consider.
1- surge protection:
After looking at those videos in last few pages,
I have to agree these companies play on the fundamantal fear of comsumers worring about lightning strikes, when,
Like you say, their "majic box" will Not stop a lightning bolt that traveled thru "3miles of sky"...
2- filtering/ AC conditioners (banks, etc):
Also agree that most good products will actually have a power supply capable to filter out noise crap in line, and deliver the necessary DC power according to its design.
Even if they have their own issues that I will state after, but first,
An example of products playing on consumer fears&lack of knowledge:
In the last Furman video , the guy plugged in a phone charger,
which was a super cheap power supply only meant to charge a battery, not a true component power supply.
So who would plug that crap in next to any audio component like a yggy?
Yet even so, it doesnt matter..
In reality that noise displayed is actually simple in origin.
Its not some complex high frequency or computer generated noises.
Its just a simple cheapo rectfied weak filtered DC voltage rippling at 60hz in same phase as original AC,
So duh, that is just AC(!).
The meter used to pick up the noise (which is obviously amplified),
is actually doing the OPPOSITE of what all power supplys (in any unit) does, which is CONVERT that same 60hzAC, and change it to a nicely filtered & regulated DC...
So One of the videos had a gross misinterpretation of 60hz noise in a monitor which would NEVER happen if functioning normal.
3- isolation:
Last video had alot of techno crap talk about some balanced power topology..
But regardless what topology the "secondaries" are implemented,
That unit still in essence was an "isolation transformer".
I havent seen any videos on what a yggy primarily would actually benefit from,
Which is a UPS for loss of outlet power..