Stepped sine wave is exactly what it sounds like...
It's an approximation of a sine wave made up of several small steps rather than one big one (a square wave).
(Basically it's a sine wave being created by a DAC that only uses two or three bits.)
A lot of equipment will accept a stepped sine wave... but it contains more noise, and more distortion, and is not a great solution.
(Stepped sine wave converters often date back to when it was difficult to produce a clean sine wave with sufficient power.)
It's also worth noting that surge protection covers a wide spectrum of products.
Even most "whole house" systems really cannot totally protect you from a direct strike...
However they will do a pretty good job protecting you from most surges that get past the big lightning arrestors and surge suppressors on the power grid itself...
If you're worried about a direct strike you should be thinking about things like physical lightning rods and big copper grounding rods...
You also need to consider things like your cable connection or your dish antenna...
Even if your home electrical system is perfectly protected a surge can still come in through a cable line or antenna connection.
And, if it does, it will go to ground through your well protected equipment, potentially destroying everything between that inlet and ground.
It's not a bad idea to at least check that the ground wires from your cable splitters and antennas are tightly attached to good ground connections.
MOVs are indeed dirt cheap... but they are also what's known as "sacrificial".
That means that, over time, and after multiple activations, they "wear out" or "deteriorate"...
At which point they may simply stop working or they may actually short internally and burn up.
Better large systems that use MOVs will give you some sort of indications when they need replacing.
There ARE higher performing types of non-sacrificial surge suppressors.
For example, series-mode surge suppressors, such as those sold by Brick Wall and Surge-X, are non-sacrificial, and carry an infinite surge current rating.
Since they actually block the surge, rather than attempt to short it to ground, they can handle a surge of any amount of current, as long as it remains within their voltage rating.
Most of those also do an excellent job of filtering line noise.
However, as a result of how they operate, series-mode surge suppressors tend to increase the supply impedance of the power line they protect slightly.
This means that, while they work perfectly for things like processors, TV sets, and moderately powerful amplifiers, they might have adverse effects on large amplifiers that use a lot of current.
(Also, compared to MOV-based surge suppressors of "similar" ratings, series mode surge suppressors tend to be larger, heavier, and more expensive.)
Stepped Sine Wave? Sounds like some kind of Sawtooth wave? In any event? Not stereo friendly.
We've been round and round about surge protection. I think we agreed that whole-house was good.
My point of use has saved me a couple times. I've been lucky, too. I was house-sitting out in Palm Springs
when a GIANT storm blew thru. and while it only lasted maybe 2 hours? OUT OF THE POOL and we had no
less than 3 lightning strikes within eye / ear range nothing major was damaged. We lost an old-school modem in a computer.
I've heard few fans of power conditioner / surge protectors for amps. My few personal data points tell me NOT to do it.
But the Soloist outlet works well with my amps, so i won't change that anytime soon.
