Sine or Multiwave function

A couple of images may help. Here is a sine wave with the third harmonic:
Fundamental-and-Third-order1

When you add them together, you get this:
sine%20with%20added%20third%20harmonic

Notice how quickly the wave raises to the top and stays there. Capacitors and other power-hungry components draw current at the top of the wave form. This waveform (multi-wave) feeds more power to what is plugged into it. This can make the component sound more dynamic, powerful.

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Ok, ye with big brain, but why might Sine sound better?

One of the minor mysteries of audio.

My guess is that not all circuits respond well to more capacitance, so to speak. I have experienced where more and more capacitors were added to an amplifier and there was a point of diminishing returns. This may be similar.

It may well also be a function of what is “better.” Some prefer ultra-linear; others, triode in the same amp and using identical tubes such as EL34 or KT88. Which is “better” is simply preference, mood, etc.

A random guess: some power supplies are designed to take smaller sips of current over the changing AC waveform, multiwave may violate their assumptions and, for example, cause it to gobble up current faster over s shorter period of time. I know that that would happen in simulations of some power supplies I played with.

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Thanks, Ted. Very interesting.

Yes, Ted and Elk are correct. The simplest way to think of MultiWave is a means of extending the peak charging time - the time the sine wave remains at its peak - as Elk was showing. That should act as if the power supply has more capacitors because there will (or should) be less ripple since the capacitors are able to charge more.

Not every product sounds better with more power supply capacitors. And remember, there are very few “rules” for high-end audio performance. We’re trying to second guess your equipment’s designer as well as adjust the synergy within your system.

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I like what MW does for my system, all PS Audio. Are the power supplies engineered with MW in mind or designs tested using it vs. sine?

A certain synergy or just luck.

Oh! Let me try! I’ve often considered the possibility that manufacturers voice their equipment under strict and non-tweaky conditions. That there is theoretical improvement possible by boosting the power (such as Multiwave), or reducing vibrations (with cones, pads, shelves, inner tubes, magic), you are changing the conditions under which the device was tested and approved by the designer and/or manufacturer. You’re changing the rules, sometimes in the direction of theoretical improvement, but the results may be unpredictable.

The guy who made my power amp, Nelson Pass thinks aftermarket power cables are silly and the cheapo he supplies is all you need.
Takes a lot for me to say this but I’m quite sure he’s wrong. The difference is so big that I just can’t imagine how he can have this opinion. Fun hobby!

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Ron, I agree with you…but Nelson is no slouch.

So I have just got my P20 and there was an noticeable increase in humming coming directly from my amp (pass x350.8). So I changed from sine to multi wave and pumped it up to 6 and the hum is at the level of the Pass plugged straight into the wall now. This seems very odd to me and leads me to wonder if the sine wave is actually configured correctly in the P20. It would make no sense to me that the house and multiwave 6 would get rid of the excessive hum and sine would cause the extra humming from the transformer.

Maybe @Paul or @JeremyBe could look into this with engineering?

@frank7036 I know you have had an issue with hum on your BHK 300 and thought you may want to mess with the multiwave, I can’t believe it but you could actually hear the hum change from the sine to multiwave and then as you increased multiwave. Freaky, but in a good way.

Anyhow, thanks @RonP for helping me with suggestions and letting me know how his system was reacting with the P20 and Pass stuff.

And thanks @JeremyBe for the initial suggestions it just took and increasing multi wave and also then doing the auto tune (it ended up at +3)

I did a whole lot of testing of the soloists and they did not negatively affect the hum as compared to a normal outlet (I had to mess around with all the electricians work and then put it all back together)

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Veneet
Does this statement mean that there is audible hum coming from your amp when plugged into the wall socket? Maybe try a different circuit. That amp should be dead silent.

@RonP There is, but when you stick your ear right next to it, I talked to Kent English about it and he said there is going to be a slight hum from it as the transformer is huge. I just ordered a emotiva cmx-2 to check to see if filtering out dc makes any difference.

I’ll test from the wall and the P20 both and into the p20 as well

Also I did try all three dedicated circuits and some of the non dedicated with an extension cord. Same amount of low level noise

I wish my BHK S300’s were silent but one isn’t. The hum is audible from the listening position when no music is playing. PSAudio fixed one but couldn’t fix the other.
Not the best outcome.

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I went over and put my (good) ear as close to my amp as I could without setting my hair on fire and there’s not a peep. Then I asked my gf to do the same and she told me I’m crazy and left the room.

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Ron,
Is that crazy for liking Porches or crazy for asking her to put her both good ears near the amp and listening for a hum… I’m just sayin… :woozy_face:

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R
Can’t be the Porsche thing because I’m Corvette crazy too.

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R, I was going for bending over and listening to a hot hum… my wife was watching me type so I waited till she went in the other room… I’m just sayin… :mask:

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You both are awesome @ronp and @cadri.

I will see after I get the dc blocker and then call Pass again and see if they still tell me the same story if it’s not DC.

Thanks again!