Do I need a 20 amp or 15 amp power conditioner/surge protector

Thanks all for your great info...very informative and helpful  -cheers

(I think the LAD just wanted to make a quick profit by selling me a $6000 power conditioner. My salesman always has been stellar for all the music gear I've bought over the years, but when it comes to accessories like cables, outlets, power, etc., I think he's less upfront - but hey, I get it - accessories are where they make their largest profit margins and he has to eat too. But in my gut I knew there was something fishy about what he said, that's why I asked for second opinions here 😀)

@carlsbad -thanks. So north of you up here in the PNW, we rarely see thunder storms or hear lightning (even with all that rain...) but we get wind storms and that's when we loose power for a few seconds, and every time the power goes out, it trips the circuit breaker in the amp. I've been told every time the varistor does that, it looses some of it's ability to protect the next time until it doesn't have any "saves" left, then my amp will unprotected. I run like a mad man unplugging my audio gear when the wind strikes, but sometimes I'm just not fast enough, and often it's the wind that hits the power/transfer station first before it gets to my neighbor hood. So, that's why I need some sort of protection. Unfortunately, my power amp weights 125 pounds and costs 5 figures, so don't want to fry it for all of the above 😬 But, yes, otherwise, I would love to be able to keep it plugged into the wall... -cheers

@carlsbad -thanks, good info to know. If I followed correctly, I think you're right regarding how my map operates. From the manual it says that when you plug it into the wall, then flip the big circuit breaker on/off switch in the back to the On position, the amp is then in standby mode. Then, to turn it on, there a soft switch (feels like a loose aluminum billet about a 1/4" round - you can jiggle it a little) hidden under a overhang on the front that you push up on and the following happens: you hear a "click" then about 7 - 10 seconds later, you hear a loud, but muffled, "pop". So, I believe that's the soft relay start you were referring to. When the power goes out, even if I unplug it from the wall, the big switch in the back trips and moves itself down into the Off position. The scary thing is, this once happened while I was listening to music and as soon as I heard it trip, I looked over at the amp and the power meter needles had shot up to the max of their range and slowly floated back down to zero... That event alone made me check my pants when I flew off the sofa.

Then, the scary event I alluded to in my original post, was after using the system this past Sat. night for watching a movie, afterwards, when the movie was over and the entire system was at idle (and no weather events - no wind, etc.) , my wife and I were talking and we heard a loud pop/bang and the smell of electrical ozone in the air, but nothing tripped or turned off - I went over to smell the vents of the Dan, McInstosh, and plasma TV but there was no electrical ozone nor arcing smell. The biggest problem is that I don't know the source of the bang, it was definitely one of those three components because that's the only thing on that side of the room. I also tested all my gear and everything operates and sounds as normal.

Everyone in another thread told me it was most likely the varistor (MOV) that blew in the Dan, but left the circuit open and so it still works, but now I have no surge protection. So, I slid the top off of the Dan and saw absolute nothing (to the naked eye and bright lights) - no swelling or burnt caps, resistors, transistors, and more to the point, the disc MOV is very easy to see because it goes across both terminals of the input mains - it still looks shiny new - no carbon soot, no discoloration, no smells, etc. My LAD salesman told me that when Dan's go, which isn't often, they just stop working altogether, etc.; that's when he suggested I buy the Niagara 5000, so that's what started me on this quest to figure out the best protection at the best price that wouldn't degrade the sound... -cheers

@jea48 Thanks for the info and video - very informative and revelatory to learn that the spike increases the further away from the panel. But mostly thanks for the formula:  3000 VA / 120V = 25 amp. So, now I kinda see why my LAD said I should at least get the 20 amp rated Niagara 5000, but of course the question is, in practically, even in loud passages, especially with lots of bass, occasionally my meter needles will go up to 400 watts at the most. So, even though my Dan is capable of 25 amps, I'm most likely not pulling anywhere close to that I would think. (Unless transients can suck higher than 15 amps without the watt meters reflecting those spikes because they're too fast for them to react to?) -cheers

@lalitk -thanks Yes, I see what you're saying and was thinking the same thing, it logically isn't adding up, especially when the Dan's manual says "plug into a 15 amp receptacle", yet, they provide a 12 gauge 20 amp cord with a 15 amp male plug for the wall end...? I see now why this hobby can stretch out into the twilight zone... It's situations like this where there is seemingly contradictions all over the place, in this case, starting with the manufacturers owner's manual and supplied cord, then all the cross talk from LAD's and hobbyist alike... 🤪 But that's nothing new... We have on one side of the aisle pure science that just looks at the numbers and the physics behind those numbers; on the other side, we have those that say the numbers don't tell the whole story... -cheers

@jea48 -thanks. Regarding:

FWIW a 15 amp circuit breaker will pass short quick current draws of 30 amps all day long without the breaker tripping

I think that's what my LAD was alluding to when he said the amp would sound better with the Niagara 5000 because it's rated at 20 amps - because transients are capable of pulling more than 15 amps from a 15 amp circuit as you explained. It's starting to make sense now. I still think the Niagara's are overkill for my purposes and I don't "think" I need a line conditioner because my system is silent at idle - all I'm really looking for is a surge protector/voltage stabilizer that will protect my power amp and not degrade it's current sound/performance. As for the rest of the gear on my media room circuit, it's all pretty low-level stuff like turntable, SACD, Blu-ray, network transport, and pre-amp. -cheers

@ditusa @jea48 -thanks gents for all the great info and interesting articles - definitely something to consider down the road. And indeed, the top of the line D'Agostinos actually require a minimum of 220v/20amp power source, so those folks who purchase his six-figure power amps have to get the electrical work done first (not a problem I'll ever have (unless I win the lottery)). I think the furtherest I may go is having the 20amp circuit installed. -cheers