What kind of THD in and out are you getting?


#1

Just curious what people are seeing as average THD in and out of their PP? I am getting 4.4% in and 0.5% out.



I must admit I am total stats nerd and love looking at the data on Powerplay.


#2

2.7% in, 0.4% out on my P10.


#3

I am curious what the scale is for THD in terms of relevance. In other words, is 4.5% THD alot worse than 0.5%? At what point can you start hearing audible differences?


#4

At this moment, I have 2.2% and 0.1%. I suspect I have better power than most as my nearest neighbor is a quarter mile away and I have my own transformer.



It is probably difficult to predict what level of THD is audible. Every piece of equipment has a different susceptibility to power flaws, we listen to different music, etc.



Perhaps some have theories.


#5

thank you…interesting that I have 100% more THD in but 500% more THD out. Clearly, the ability of the PP to reduce THD is not linear. BTW, you do seem to have good power! Living in Socal my nearest neighbor is about 7 ft away on either side!


#6

The numbers themselves, as well as their relationship, vary. I find the reported decrease in THD to typically be about a factor of ten.



Keep in mind that the THD measuring circuitry is fairly modest (the money was wisely spent elsewhere) and is only a rough measurement. The equipment necessary to provide a precise measurement is very expensive.



There are times I see 5% THD or more. I also see occasional brownouts with voltage at 108 or the like. The incoming power is a lot more variable than I would have guessed.


#7

2.6% in and 0.4% out on my PPP.

L-)


#8

Your THD out on a Power Plant should hopefully be 5 to 10 times lower than the input depending on the load.


#9

2.4 in; 1.2 out


#10

@David, not to cause any alarm but according to Paul’s response you should be getting in the range of 0.2-0.4 THD out. I wonder if there is a problem with your P10 or if something in your system is causing this? All this may not even be relevant because I am still not sure at what point THD even impacts the sound.


#11

Currently 2.5% in and 0.1% out. 119.7V in and 120.4V out. 219 watts powering SS equipment at the moment and listening to Renaissance music at moderate volume. An easy load.



I have seen much less improvement in THD when operating tube equipment (power factor is a bigger issue as I recall and much greater wattage) and when the voltage correction is much greater.



David is running a very serious, incredibly fascinating tube amp which draws more than twice the wattage I am running currently for my entire system. His P10 gets a workout. :slight_smile:


#12

@tboooe - Hi - nope, nothing wrong with the P10. But thanks for asking - this is what audio brethren are for.



The P10 (not sure if this is true of the P5 or P3) allows you to trade off between voltage regulation and distortion.



From the manual: "If the P10 is being used in an area with erratic input voltage, or input voltage that is consistently higher or lower than the level 120V or 240V (depending on region), it is suggested that the High Regulation selection is made.



As general guidelines, tube equipment and electrostatic speakers will benefit from the High

Regulation setting, whereas solid state amplifiers and video equipment will benefit from the Low

Distortion setting. In the incoming AC is within 5V of the base-line output, either mode will offer

great performance. Outside of five volts, the user can maintain voltage regulation at the slight

expense of THD control with High Regulation, or can maintain THD control at the slight expense

of voltage regulation using Low Distortion."



In my situation I see voltage from the low 220s to up to 256. This because the UK has yet to fall totally in line with the EU directive on voltage harmonisation - they are allowed this range for now, but eventually must get it down to 230 nominal with similar allowance for the lower limit but with a significantly reigned in upper limit.



Since I run a boat anchor amplifier that was made in Italy for 230V, and has a pair of paralleled 845s on each channel - very high voltage - I opted to pin the voltage to 229V, and put up with the slightly higher THD (reduction by a factor of 2 is expected in this case, and that is what I get).



I imagine this approach will extend the life of the amp - which costs considerably more than a P10 and is worth protecting. I also keep it on the HC zone so I start it up from the P10 directly everytime.



The SQ in this configuration, with the multiwave setting on, is FANTASTIC.


#13
David said: trade off between voltage regulation and distortion.

I forgot about this option. The P5 has this as well. It is perfect for your situation.

David said: I see voltage from the low 220s to up to 256.

YIKE!

David said: The SQ in this configuration, with the multiwave setting on, is FANTASTIC.

Do you notice any increased transformer hum when running multiwave?

#14

Elk said: David is running a very serious, incredibly fascinating tube amp which draws more than twice the wattage I am running currently for my entire system. His P10 gets a workout.


It runs a tad warm, it is true.

Attached is what I think is a good review - partly because I think they actually spent to the time to listen to the amp and made insightful remarks about it, and partly because I agree with what they said :)

<fieldset class="gc-fieldset">
							<legend> Attached files </legend> <a href="/wp-content/uploads/attachments/55412=1907-23c3d45d391baa5bd4ea06b4e087ba.pdf" target="_blank" class="gc-files">/FileUpload/00/23c3d45d391baa5bd4ea06b4e087ba.pdf</a> <span class="gc-filesize">(874.5 KB)</span>Â </fieldset>

#15
Elk said: Do you notice any increased transformer hum when running multiwave?


I haven't noticed a big difference, but maybe I'll try tonight to see if I hear a small difference. From the listening position there is a BIG difference with multiwave on, that is for sure.

#16

Yikes, you guys are drawing some serious wattage! I barely break 104 watts most of the time and its plenty loud for me! I think PS Audio needs to make a P1 for low power people like me!


#17
David said:
Attached is what I think is a good review

Thanks! This will be a fun read. This is a neat, neat piece of kit.

tboooe said: I barely break 104 watts most of the time

I bet there are some pretty good peak loads at time, plus the additional headroom is always a good thing.



#18

I bet there are some pretty good peak loads at time, plus the additional headroom is always a good thing.


That's what I don't understand. Looking at the history on Powerplay, the peak wattage is very close to 104 regardless of how loud or low play music. It's like my amp is highly biased in Class A.

#19

The first watt of power output is the least inefficient. The amp needs X watts to operate which it uses regardless of output. Then there is the power actually used to drive the output to the speakers. Most of the load you see on the P3 readout is the quiescent demand.


#20

In the case of my Audio Research ref 150, X=750watts! I’m gonna need to plant a lot of trees if I want to stay carbon neutral!



Incidentally on my P10 in Australia, THD in 1.7%, THD out 0.1%, hence I usually use low distortion setting rather than high regulation.