Variable Multiwave Update For P5/P10 - Interesting Results


#1

My first thought was to skip the Variable Multiwave update because I have never heard any benefit from Multiwave, either with the PPP, P5 or P10. After reading about the update, my curiosity was piqued by the variability feature. I installed the update in my two channel system’s P10. I did not hear any benefit from settings 1-3. Settings 4-6 produced the same loss of clarity and detail that I heard in previous MW trials.



HOWEVER, I noticed that when MW was OFF, I heard improved clarity, detail, bass growl and bass articulation that was not there prior to the update. I then noticed that the outbound THD was 0.1% whereas it was 0.4% before. I confirmed with oscilloscope noise spectrum measurements that the outgoing THD was significantly lower than before.



I installed the update on my home theater system’s P5 and P10, but I have not done any listening and viewing evaluations yet. The outbound THD on those regenerators also fell from 0.4% to 0.1%.



I will post measurements and listening and viewing evaluations later.



Questions for PS Audio:



1. Why wasn’t the significantly lowered outbound THD mentioned in the announcement for the Variable Multiwave Feature?



2. The Variable Multiwave announcement says “Note that the [SD] card is installed upside down”. A picture is shown with an SD card with the label side down and contact side up. My P5 and P10s take the SD cards with the label side up. Do some PSA products take SD cards upside down and the announcement writer assumed that all PSA products do? This is of concern because someone might try to force an SD card into the slot upside down.



3. Has there been any thought given to making firmware upgrades downloadable from the Internet? Both my P10s and my P5 are connected to the Internet. It would be great if I could download firmware upgrades like I do with my Blu-ray player and plasma television.


#2

By adding multiwave strenght the output voltage is dropping a bit to. Dis is due to the thirth harmonic which is on the other side of the neutral line when the sine reaches the top. Sorry for my bad technical english.

So in theory the output voltage should be linked to the thirth harmonic strenght. Maybe you could try to add a few volt and see if the clarity and detail increase again. You can use the power output level it should be the same level as it was with sinewave. Don’t go further then 5% with adding extra voltage. Or better lower the voltage a bit and start listening from there!


#3

My explanation for this is. That with multiwave the storage in the capacitors is better. The loading time is longer per powercyclus. But this is done with lower voltage so your system power is reduced a bit too.


#4

It seems I forgot something. It is about average voltage. Toplevels are about 1.41 higher. So the capacitors are loaded with higher voltage due to the average loading time. So there’s no need to increase the voltage. You can try to decrease a bit.

My mistake!


#5

I have to think about the powerdrop showen on the display when multiwave is active. Probably the transformer losses are bigger with sinewave. This could be the reason because the average voltage is a bit higher with multiwave in a powecycle. So if I’m right the connected equipment takes advantage in the transformer and in the capacitors. Very interesting stuff!


#6



I also was not anxious to upgrade since I do not use multiwave. Your report of lower sinewave distortion inspired me to do so. The upgrade was successful but I have no decrease in measured distortion. It was 0.5% before and 0.5% now.

#7

I think the biggest difference can be found in the size of the power supply ripple current, which goes down as you extend the charging time. This means the average DC level goes up slightly and the peaks of the ripple go down. The exact same thin g happens if you were to add more power supply capacitance to your connected equipment’s power supply.



What’s truly cool is that by externally “adding” more power supply capacitance to the supply, you don’t get any negative effects. I’ll give you an example. In many cases on products I’ve designed there’s an effective upper limit to the value of the input power supply capacitors. Too much/many and the sound seems to slow down and get sluggish, too few and it leans out to an uncomfortable degree. We assume that the designer of your connected equipment already knows this and did their best to give the products what they need/want.



But adding a longer charging cycle, as we do with MultiWave, gives you the benefit of more caps without actually giving you more caps and you get all the positive bennies and none of the negatives. By giving you variable MultiWave you can now tune your system to best affect.


#8

@st50maint It shouldn’t change the output THD but why is it you don’t use MultiWave?


#9
@st50maint It shouldn't change the output THD but why is it you don't use MultiWave?
Paul, it appears that some of the responders have not understood DarqueKnight's original post. I have copied the most relevant parts below:

"HOWEVER, I noticed that when MW was OFF, I heard improved clarity, detail, bass growl and bass articulation that was not there prior to the update. I then noticed that the outbound THD was 0.1% whereas it was 0.4% before. I confirmed with oscilloscope noise spectrum measurements that the outgoing THD was significantly lower than before.

I installed the update on my home theater system's P5 and P10, but I have not done any listening and viewing evaluations yet. The outbound THD on those regenerators also fell from 0.4% to 0.1%.

I will post measurements and listening and viewing evaluations later.

Questions for PS Audio:

1. Why wasn't the significantly lowered outbound THD mentioned in the announcement for the Variable Multiwave Feature?"



#10

Not sure why you are seeing that. If you disconnect your equipment from the Power Plant and change MW settings with nothing connected, it will probably not lower the THD.


#11

I believe he is saying the firmware update itself lowered the THD percentage, running in sine wave mode.



That is, sine wave THD is lower after the update than sine wave THD before the update. Apples to apples.


#12
Not sure why you are seeing that. If you disconnect your equipment from the Power Plant and change MW settings with nothing connected, it will probably not lower the THD.


Paul, just to make sure we are on the same page. My understanding is that DarkNight says that with multiwave turned off the distortion is now 0.1%. Before the upgrade, his distortion was 0.4% with multiwave turned off.
I do not see the same reduction in distortion that he does with multiwave turned off since updating my P10.


#13

Elk,



That is how I read it as well. I also think there is too much being made over a small drop in THD. .3% less distortion is not something that I think we can easily hear, if at all. We try to get all of our components operating at their max levels, a little here, a little there, and then hopefully it adds up to something that bears a difference.


#14

Oh, sorry, I misunderstood. There should be no change. Several refinements were incorporated into the metering system’s accuracy a long time ago and these, of course, remain as part of the firmware upgrade. Perhaps he started with older firmware that didn’t have these refinements?


#15

This would make sense, Paul.



I saw no change, but was previously running firmware which I had received from Marcus six months ago.



I would like to know if the THD % increases again with the original firmware reinstalled. As a second test, does the THD % increase with the attached firmware loaded?



(The date on the attached firmware refers to when I received it.)

Attached files /FileUpload/48/ab7f5b364d8d019c060a08fddd335b.zip (537.1 KB)Â


#16
Oh, sorry, I misunderstood. There should be no change. Several refinements were incorporated into the metering system's accuracy a long time ago and these, of course, remain as part of the firmware upgrade. Perhaps he started with older firmware that didn't have these refinements?


My two channel stereo system's P10 was purchased in November of 2011. The P10 and P5 in my home theater system were purchased in December of 2011. I had done no firmware upgrades since purchase, so whatever firmware was shipping in November and December of 2011 is what I had previous to the Variable Multiwave update.

The oscilloscope Fast Fourier Transform plots below show the differences in noise spectrum among the power signal from the wall and the P10's output prior to and after the Multiwave update.


Figure 1. FFT plot of power from the wall.


Figure 2. FFT plot of power from the stereo system's P10 prior to Variable Multiwave update, meter read 0.4% outbound THD.


Figure 3. FFT plot of power from the stereo system's P10 after Variable Multiwave update, meter read 0.1% outbound THD.

The amplitude of the 3rd harmonic in the P10's output prior to the update was 0.398 volts. The amplitude of the 3rd harmonic after the update was 0.158 volts. Every horizontal dot in the plots represents 10 Hz of frequency. Every vertical dot represents 2 dB of amplitude. The large spike on the left of the plots is the 60 Hz power signal and the largest spike to the right of it is the 3rd harmonic at 180 Hz.

Therefore, my P10s and P5 are actually producing less harmonic noise in their outputs. Did any prior updates address noise reduction issues? There has to be some explanation as to why I am measuring less output noise and why I am hearing improved performance. The improvements I hear could be dismissed as imagination, but I was not expecting any potential benefit from the update other than improved Multiwave performance, so there was no expectation bias with regard to improved performance aside from the Multiwave update. Of course, the oscilloscope measurements cannot be attributed to imagination.


Figure 4. Stereo system's P10 status screen after Multiwave update.

#17

Very, very interesting. Thanks for posting the graphs and additional information. Where the measurements all taken on the same day, back to back?



DarqueKnight said: Of course, the oscilloscope measurements cannot be attributed to imagination.


Indeed not, unless you are in some unknown way really sneaky. :slight_smile:



DarqueKnight said: The improvements I hear could be dismissed as imagination, but I was not expecting any potential benefit from the update other than improved Multiwave performance, so there was no expectation bias with regard to improved performance aside from the Multiwave update.


Completely reasonable. Did you notice a change in sound first and then went to investigate?



If you have the energy and time to do so, I would be very curious to learn what you measure and hear after installing the firmware I posted above.



Thank you again for your analysis. Fun stuff.

#18

Multi-wave has taken a black and white signal, and made it now, a color reproduction.


#19
Very, very interesting. Thanks for posting the graphs and additional information. Where the measurements all taken on the same day, back to back?


The wall and P10 post update measurements were taken on the same day. The pre update measurement was taken months prior.

Did you notice a change in sound first and then went to investigate?


Yes.

If you have the energy and time to do so, I would be very curious to learn what you measure and hear after installing the firmware I posted above.


I would actually like to do better than that. I would like to go back to the original shipping firmware, from November 2011, then do listening and measurements with each successive firmware update up to Variable Multiwave.

I have firmware updates:

PWRG0020
PWRG0024 (The one you posted above)
PWRG0027 (Variable Multiwave)

I need the original firmware that shipped with my P10 in November 2011 and any firmware updates not listed above. I have submitted a service ticket requesting the original firmware and any other updates I don't have.

#20

Cool. This will be fun.