Ok, yesterday I have done my dedicated lines, well my electrician did it but I guess I will take all credit for it and he just get my check. I have right behind my rack with PP3000 and power measuring equipment, on the wall 3 groups of receptacles: One duplex with best sounding house line and two dedicated 100A lines with Nima L15-30P twist lock outlets  each, paralleled with 20A standard duplexes outlets. The Nima L15-30P is 30A rated and I use 40A circuit breakers on each dedicated lines (better quality then 30A breakers). I have two lines each of them represent a half of 240V, each half of 120 do sound and do measure differently.

So, the biggest question: was it worth it? I do not know yet. Last night I have some listening, in fact not me but a local audio guy come to my place and he insisted that sound was significantly better. He however did not hear my playback with PP3000 but only with PP2000 and I feel that PP3000 does cover his “significantly better” comment of his.

I did not do my own critical listening as he occupied my listening char all last evening but my sentiment that with dedicated line I did not have any worsening of sound, I also did not detect that it was “better”. It was basically the same sound that I had since I got the PP3000. I did not have a chance to play with different lines as my current PP3000 has some minor issues to source from different  power lines  but I think we already have discover the might be the reason for it. I think in few days I will be able to use my PP3000 with multiple incoming lines and at that time the dedicated lines will break-in a bit.

Also, it is difficult to make a proper assessment of dedicated line benefit as the quality of electricity in the given day needs to be factored in. So, I think with a few weeks I will be able to get composite feeling if generally my dedicated line gave me any notable improvement across the board. If the damn PP3000 had the remote switch then I would be able to say that, factoring in and relating it to the sound of open lines…

At this point there are a few questions that I am wondering:

1)  Does a dedicated line have advantage if PP3000 is used?

2)  Will Sound be benefited if the PP3000 driven by 240V (essentially a balanced line)?

3)  Will PP3000 be benefited if I put in front of it 240V to 120V isolation transformer?

4)  Can I inflict any treatment over the dedicated line to make the minor residual fluctuation of sound not detectable (presuming that it still come from electricity even thought I have no evidence that it comes from electricity)

5)  Will it worth for me to source the dedicated line not from the very first circuit breaker on my main panel or I need to go and install a dedicated run directly from service entry across a dedicated electric miter?

6)  Would it be beneficial to flip the element of the dedicated line to cryogenic elements?

7)  Would it worth to me to apply any gold or silver high voltage paste to the dedicated line’s outlets and circuit breaker (Johanson or Walker super conductive silver paste, 3M silver paste, Stabilant 22, Solar panels WTS silver paste, Deringer Gold Treatment, ProPlate electroplating, Conducto-Lube Silver grease, Circuitmedic’s Gold Contact Plating, PCB kit from Gold Plating Services and etc, etc, etc..)?

8)  Does it make any sonic sense to use any other power treating devises before or after PP3000?

9)  What to do with my PC (DAW) and hot to power it (dedicated PP2000, insulation transformer and so on)?

10) Shall I hire electrician and to renovate my power service entry?

11) What kind inducement shall I invent in order to make the PurePower people to implement bypass switch into their unit?

They are the question that in one way or another I will be looking to answer in coming time. Feel free to share the results of your experiments on the subject.

Romy the Cat wrote:

Whatver PurePower dose or dose not does but it works 100% perfect to address problem with dimmers.

I sat down today to listen what is going on with sound of my dedicated lines. Last night I shot down heating in my house and let the dedicated lines to care 3K heater (1.5K on each phase split) for enter day. So it is not brand new copper anymore. I do not thick that it break-in the lines but it did move it from the virgin stage

So, I have the whole system powered from PP3000 and have 3 chooses of the power sourcing for PP3000, in fact 3 power outlets behind the PP3000.  Memorize those 3 chooses as they are important.

Power Source #1 (PS1): Dedicated line from A phase of the 240V spit.

Power Source #2 (PS2): Dedicated line from B phase of the 240V spit.

Power Source #3 (PS3): House utility line that was selected by me as the best sounding. Uses the same phase split as PS1

It is 7PM, no light in the house only one single led at my listening table. The system is plagued into PS1 and the sound is nothing short of spectacular. I do not know if it is good electricity day or an average day but the sound is very good.  Switched PP3000 to battery operation. The sound is virtually identical. There is some very-very-very minor difference with advantage to battery but so minor that I would perfectly discard it. PP3000 is loaded at 42% and after approximately 45 seconds of battery operation the PP3000 shuts itself down. I have no idea why. The unit restarts itself (!!!) and as it stats the miter shows 89% of battery charge. As far as I concern it is something fuck up in my PP3000 as properly operational unit shall not shut itself down until much lower discarded. My PP2000 can draw down to ~25% and then shut itself off. Probably in PP3000 they use higher voltage batteries (96V vs. 72V) but they might not change the discharge logic and the 96V PP3000 still use the 72V logic of PP2000.  I do not know what is going on and I do not have second PP3000 to verify it. Anyhow, testing the PP3000 is not my objective now but I care about testing of my power lines.

Switching between the PS1, PS2 and PS3 do produce different results. Not day and night but different with one slightly better than another. It is interesting but the results are very much related to the fact what electricity I use in house. Now you will be very surprised. Juts this morning I was insisted in dialog with LX above that my PP3000 is immune to the bad sound from dimmers.  Well, with use of the dimmers in my house (I can use them ONLY in PS3 line, which is the same as PS1 phase split) the sound was changing BUT I am not convinced that with all dimmers heavily engaged the PS1/ PS3 line sounded inferior then PS2 (where there is no dimmers). Read it again – this is VERY interesting conclusion. The sonic difference was there but it was not only factor of dimmers but something else and I do not know what it is. Unfortunately I was not able to go farther as flipping between lines in my current PP3000 has some twist and sometime requires to restart PP3000 along with the enter system.  I need to have power source transition completely transparent as then I will continue this test. What I detected is that when the PP3000 starts and begin to charge the battery then it has very slightly different sound then what the battery is completely charged. This is acid battery as it always being charged but apparently the charging current doe has some impact to sound. 

Anyhow, acknowledging that I do have minor but notable difference between the power lines I am not sure that I know why the difference exists and what kind contribution the house utilities and dimmers have to it. I am sure I will figure it out but I do need a methodologically stable and predictable platform to base my observations. Now I do not have it die to the various reasons.

So, here is some data.

This is the picture of my mean Pussy. It has no relations to power lines but I do not care – she has relations to anything.

Here is the picture of my two dedicated line outlets

Here is the PS3 line with no lights in house except one dimmer at FULL power.

Here is the PS3 line with 6 dimmers engaged in half power

Here is the PS1 line (the same phase split) with 6 dimmers engaged in half power. You might see that measurable noise is lower.

Here is the PS2 line (different phase split) with 6 dimmers engaged in half power. You might see that measurable noise is much lower.

Here is the PS2 line with no light in house. Note a lover voltage – I have no idea why.

All images above were with PP3000 unpledged. Now it is something VERY interesting. The image below is the PS1 line (dedicated line that is the same phase split as the whole house) with 6 dimmers engaged in half power. It has to be the same as 3 images above BUT now the PP3000 connected to PS1 line and powering all system. The distortion that you see at the image: Dedicated_power_lines_5.JPG not there and PP3000 injects back to the power line a lot of own HF noise. If I go with faster time/division then you will see it in 20 kHz-30kHz. In the image below it make the wave fatter but in fact it is the PP3000 sampling nose coming back to power line. So, it looks like this return noise of PP3000 overrides the noise of the power line! What is very interesting that I got the same image for all 3 power lines when the PP3000 is plugged into the given power line.

I do not even mention that regardless what power lines the PP3000 is using the output is not distinguishable (visibly), regardless now noisy the line I was able to make. Still, the sound, as I said before, have some differences. What would be VERY interesting is to find correlation between the sounds of open power line under different noise condition and the sound of the same line after the PP3000. Then it would be possible to form the best operation scenario for PP3000 but to do it I need the fucking bypass switch in PP3000 !!!

Anyhow, this post does not do any conclusion but juts shares data. It provides more questions than answers but it does define the lay of the land and does form proper questions in my view.

steverino wrote:

You say that the dimmers are on PS3 line only. However, when you turned dimmers on, the PS1 And PS3 lines had "changed" sound that you are "not convinced" is inferior to PS2. First, how would the dimmers affect PS1 since it branches before the house line directly to the PP3000?

Do not forget that dimmers to a different degree affect all lines. The PS1 and PS2 lines are the same secondary of step down transformer on the poll with neutral acting as center tap. So, the events that took place on the one side of the secondary naturally propagated to another one. I did make a phone call to a transformer guy and consulted with him on the subject and it is a bit complicated how this penetration takes place.

steverino wrote:

Second, are you saying that both PS1 and PS3  were "changed" identically or in highly similar fashion compared to PS2 (ie PS1 and PS3 now sound the same albeit changed from what they sound like without dimmers on) OR do you mean that PS1 and PS3 both had "changes" to the sound but in distinguishable ways between them?

I would not insist in one or other. I do feel that it is not as direct and straight forward when PP3000 involved as it not only “fix” the problem by regeneration but it looks that it also equalize the condition by squirting into the dirty lines own noise. It would be VERY beneficial to hear the sound of open line with PP3000 plugged into the same line but do not power system from PP3000. This would give a lot of data to interpret the result but to dot I need to have a bypass switch in the PP3000. I have many components and to unplug them and then to plug them in different outlets is very unpractical and too troublesome.

steverino wrote:

Third, I assume you realize that the term "not convinced" implies a significant possibility that you will be convinced. Therefore, what were the nature of the changes that left you "not convinced" that Ps1 and PS# sounded worse than PS2 when the dimmers were on? Thanks for all your effort in examining these issues BTW.

Sure, everything is on the table. This is why I insist that at this point I do not have any even preliminary concussions. It would be very simple if I plug the PP3000 into the dirtiest like and had worst sound but it did not happen. So, it will take more efforts, more time and more methodological purity to figure out what would be optimum configuration.

Romy the Cat wrote:

The point that you have EU (240V version) is well taken....

Lx_ wrote:

The effects on sound can be described either globally or in details. Globally the music flows less, the sense of musical phrasing is diminished, sound tends to tighten, feel constricted, dynamics are also reduced. When trying to analyze what is wrong, one notices that timbres are less accurate, dynamics suffer and transients are handled less favorably. The effect is similar to a reduction of clock quality. Yes it has occurred to me that the clocks in my soundcard may be subject to noise and that may explain the problem, but since the PC is plugged to PP which is supposed to filter noise out it does not explain where the noise comes from except through PP.

I need to say that Lx’s post above a few days back made me uncomfortable. From one side I made many experiments and insist that PP3000 (I made those experiments with PP2000 in fact) does not effected by my dimmer/s. From another side Lx made a seldom intelligent post with reasonable description of sonic effect that in my book always give credit. I referred the Lx’s finding to the possible fault of his PP2000, to the fact that he runs 220V unit and in entire 220V topology. However, it still left in me some itch to go to the bottom of it.

So, today I decided to redo my experiment with my dimmers. So I did and the result was not what I reported before. To be honest the result is not exactly what Lx reported as well. However I am not in the business to make conclusions and all that I can do is just to describe my experiments and what I witnessed.  If you care about the electricity problem and particularly if you use PurePower Units then read on- it will be VERY interesting, hugely educational; at least it was for me.

So, whatever I did was with today electricity, whatever it was. My estimation is that electricity was not bad today. I do have means to hear it and to measure it, not only with scope but with PS Audio Noise Harvester. The Noise Harvester is phenomenal little tool. It does not improve sound as PS Audio foolishly claim, in fact it destroys it but it act as very good indicator if current noise, similar to the Noise Sniffer. I plug it in, to see the noise and then plug it off. So, from what I know and hear the electricity today is not bad and the sound of playback is fine, something that I call “my default sound”. I need to note that my “default sound” in evening imply to use at least one of 5x75W lights dimmed to perhaps 15-20W.

I slide the dimmer up and down and was not able to detect any significant change in sound. It felt that with dimmer at full power (bypass mode) the sound got a bit zippy but to a very minor degree. The PP3000 is plugged in dedicated line, the better sounding phase split (where 9 oft of my 11 dimmers sit). Then I walked around the house and turned off all lights off, all 3 computers off (except servers that run from own UPS) and the PS of laptops.

When I sat to listen I was VERY surprised. The sound was too zippy. Not even zippy but like it was SET amp driving a speaker with too much idle output tube. The transients were a bit faster then need to be and the dynamics was a bit to barbaric. It was in way like a bad SS amp, not laterally but it was very much not the sound that I am accustomed. Then I turned my default SS listening light dimmer all the way up and begin to lower the light. As I reach my 70-80% of attenuation I noted that sound got very little softer. I would never be able to detect it blindly – it was extremely small and I still do not know if it was not wishful sensing. Then I took another dimmer and begin to do the same. I felt that the effect was the same it got a bit softer but nowhere near what I like.   Then I took portable lamp, pit in there 300W bulb, handheld portable dimmer and plugged into in the same power outlet where my PP3000 was plugged. As I got ~50% of attenuation my sound got fixed. There was no lost in bass or anything else but there was a very nice and balance softening sound, it was like a drop of very fine oil in the perfectly operational by dry gears. It just got all connected and smooth.

Then I turn all of my 11 dimmers and not only turned then but tuned them by my scope in-phase, or made their distortions to be the worst possible in the scope. The sound literally died. It was what Lx described but to the much meaner degree. It was dry, with much less defined bass and with eaten all details and colors. In other word it was exactly what I would like to have – it was the predictable and repeatable REASON.

Making more experiments I concluded that 4-5 dimmers in-phase do fuck up sound. The 7-8 dimmer in random attention do not fuck up sound, however, two dimmers in-phase with powerful load if then sit in the dedicated like do impact sound. Again, in this case the “in-phase” means that their distortions from attenuation compliment each other in scope.

So, I do not set the dimmers before “in-phase” and I never use more then 2-3 dimmer at the same time during listening, so it was probably why I did not recognized that dimmers might affect my Sound through the PurePower units. 

Then I asked myself why I had with no dimmers that zippy sound. Eventually it hit me: I have another PP2000 powering my DAW in basement. I went there and shut down the PP2000. As I got back, and with no might in house I immediately witnessed glories sound, it was absolutely perfect.  I begin to slide one dimmer from my “default listening light”. I practically recognized no difference. Even with the heaviest attenuation I was not able to hear that sound softening effect. I also was not able to see the contribution of this one dimmer in scope, even though the Noise Harvester did pick it up very distinctly. I did another 3 dimmers, with no care of them to be “in-phase”. I would say that I did detect some move of contrast but it was VERY minor, to the point of be negligible. The use of one 300W dimmer on the dedicated line was more effective and was noticeable.

So, what I learned? I got rid of my 5x75W lights in my default listening light and replaced then with 5X15W and I got rid of the dimmer on this light. It was not necessary but I gave me the option to use one or two dimmers in my house with no danger the I will fuck up Sound. I learned the there is no way for me to use my PP2000 anywhere in my house, unless in my Opera Room as when I am in there I do not care how my audio system sounds. I also learned that my dedicated line does work very effectively, slightly attuning the nose coming into PP3000. Another thing that I have learn the dimmer are much more devastating in the same phase-spit and less devastating on another phase-spit. The biggest learning that I did was recognition the need to use some power discipline in my house if I would like to maintain good sound for Audio; lucky me I do not live in apartments and it would not be difficult for me. The PP3000 certainly a great protector again the dimmers but it apparently has a degree of electricity nastiness beyond which is can’t do a lot anymore. I will try sometimes to put a large isolation transformer before the PP3000 and to see how it works.

All above are not concussions that pretend to be universal but my private lessons that I learn. You might have different outcome as the condition are too different in my and your case. Still, I felt that I owe this disclosure to LX, to myself and to some Truth and Reasons that we all looking for.

Romy,

    Your findings are more congruent than not with my own experiences with  different systems and environments.

Dedicated lines:.  My experience with a dedicated line was when I was in a detached house. The line corresponded to your first dedicated (inhouse) line. In slight contrast to you I noticed a mild (but only a mild) improvement compared to the house line. However I didn’t have dimmers or other nasty devices and I lived in a smaller town about 60 miles from a big city.  It seems that if there is any path whatever then the “dedicated” line will experience leakage from other lines. I think the only way around this is to have a second “drop” from the utility going to a separate wiring installation (or separate room/building).

Line distortion:  I think that much of the distortion from house non-audio devices (refrigerators etc) is ameliorated by randomization of peaks and troughs. The key is how varied the other devices are (assuming they are Not on the same circuit as audio). You have an unusual situation because you have so many dimmers (one type of device).

Power regenerators: They seem to behave as another component in the audio system rather than something apart or preceding it. I had a PS Audio power plant at one time and while it did some good things It was inconsistent in its effects. I assume from your experience that the Pure Power regenerators are better but they also seem to behave as components in the audio system. For example, I use a VPI SDS regenerator to operate the turntable. When I stuck a balun in between the wall and the SDS I noticed a reduction in noise level but like you I also noticed a negative effect on the sound. However, if I stuck the balun between the SDS and the turntable (ie the turntable plug into the balun and the balun into the SDS) then I heard noise reduction Without a negative effect on the sonics. But note that the SDS – balun – turntable motor have no direct connections with the audio components.

As a side note because of my dissatisfaction with the existing regenerators (other than the SDS) I  ended up going with PS Audio baluns (UO). However, I found that each component had to be plugged into a separate balun to achieve significant results. The baluns are then daisychained back to the wall. The balun is supposed to reduce noise bidirectionally and it does seem to do that. (Most reviewers did not use a separate PS Audio balun for each component. leading to equivocal results IMO). I felt that the sound was more natural with the baluns than the power plant. The drawback is that I’m still at the mercy of the utility to some extent since I have somewhat less insulation from their garbage. I will try the Pure Power regenerator this year and hope it does better. But I suspect I will still need baluns if the SDS experience is any guide.

As for your installation I agree that was a brilliant idea to have the two splits on the (improved) dedicated line. I would also be interested in any experiments you do in trying to buffer the individual components from each other.

steverino wrote:

You have an unusual situation because you have so many dimmers (one type of device).

steverino wrote:

Power regenerators: They seem to behave as another component in the audio system rather than something apart or preceding it. I had a PS Audio power plant at one time and while it did some good things It was inconsistent in its effects. I assume from your experience that the Pure Power regenerators are better but they also seem to behave as components in the audio system.

I more agree then disagree. It is very easy to go astray with recognition of power regenerators as some kind of power improving devises. For sure they do improve power but they also have own sound, own sound that might not necessary relates to the power improvement, or put in this way: relates but not so straight forward. I happened to like a lot how the Pure Power sound, is it strictly related to improvement of electricity? Hw, perhaps but I do not have a definitive answer. Put in this way: if I run Pure Power Company then I would consider making a class A or A/B amplifier with Pure Power instead of power supply…

clarkjohnsen wrote:

...I hope y'all are attending to AC polarity alignment, else many of your decisions may be erroneous. I've written so much about this perfectly audible phenomenon that I don't feel like doing it any more, so I point you to an excellent comprehensive article, beginning with an excerpt.

I did not see you write or say anything about AC polarity; you constantly keep stressing Acoustic Polarity but not the AC polarity. At least I did not witness it. Anyhow, AC polarity is for sure a well know phenomena (it was multiple times mentioned at this site) and no one argue that it has to be properly handled. Thankfully with proper following electrical code and proper attention with equipment the  AC polarity shall not be a problem and it take care itself.

clarkjohnsen wrote:

WHAT YOU NEED TO BE AN OBJECTIVE SCIENTIST. Almost all of your audio equipment has a transformer in it that serves as a source of power for the circuits inside. Not all manufacturers hook up their transformers so as to minimize voltage leakage to the chassis, otherwise called the "chassis to ground potential". One can measure this by purchasing some of the most expensive objective testing equipment known to man and Julian Hirsh. What you will be measuring is the amount of voltage running around in the chassis of your audio stuff. The preferred voltage is the lowest voltage, which will save you from making dreadful subjective decisions. http://www.boundforsound.com/tweak.htm

Actually AC polarity has nothing to do with voltage leakage in transformers. I do not know what Julian Hirsh measures but flipping AC polarity you do not deal with voltage leakage. Regarding the article. I did not read it. I glance from the end and find a reference to Bybee-Sucker as the best AC line filtering device of its kind”. I do not know who wrote it but he is in idiot as Bybee devises are piece of crap, made to use only by deaf morons. 10 year ago I participate in blind test what I with 100% accuracy was able to detect the presence of one single Bybee-Sucker in system – I truly hate that shit and I discard any authors to patronize the Bybee crap.

clarkjohnsen wrote:

...I hope y'all are attending to AC polarity alignment, else many of your decisions may be erroneous. I've written so much about this perfectly audible phenomenon that I don't feel like doing it any more, so I point you to an excellent comprehensive article, beginning with an excerpt.

I did not see you write or say anything about AC polarity; you constantly keep stressing Acoustic Polarity but not the AC polarity. At least I did not witness it.
 
CJ: I wrote as early as 1988 in The Wood Effect, and have been talking about it since even earlier. Plus numerous mentions in my columns and on Audio Asylum. I'm huge on it!

Anyhow, AC polarity is for sure a well know phenomena (it was multiple times mentioned at this site) and no one argue that it has to be properly handled. Thankfully with proper following electrical code and proper attention with equipment the AC polarity shall not be a problem and it take care itself.

CJ: It does not take care of itself (what does?) and following the code doesn't get you there either.

Actually AC polarity has nothing to do with voltage leakage in transformers. I do not know what Julian Hirsh measures but flipping AC polarity you do not deal with voltage leakage.
 
CJ: Indeed, it is current leakage... but measured by the difference in potential. The article was correctly, if ambiguously, phrased.

Regarding the article. I did not read it. I glance from the end and find a reference to Bybee-Sucker as the best AC line filtering device of its kind”.
 
CJ: The article was written nearly 20 years ago; much has changed. Had you read it... well...

I do not know who wrote it but he is in idiot as Bybee devises are piece of crap, made to use only by deaf morons.
 
CJ: As with power cords and everything, YMMV.

10 year ago I participate in blind test what I with 100% accuracy was able to detect the presence of one single Bybee-Sucker in system – I truly hate that shit and I discard any authors to patronize the Bybee crap.

CJ: There are, of course, several models and succeeding generations. To which do you refer?

c

clarkjohnsen wrote:

It does not take care of itself (what does?) and following the code doesn't get you there either…. Indeed, it is current leakage... but measured by the difference in potential.

Romy the Cat wrote:

PP has the ultimate tool that allows detecting a LOT about its operation. Do you observe the same behavior as you describe when you pull out the power cord and let the unit to run from internal battery?

Romy the Cat wrote:

Whatever problem you have is less likely related to ground. If I was you then I would check if the unit has full profile sinusoid at full load. Use 10:1 probe, any type of analog scope (you can pit it used for $30) and analyze the bottom and top of the curve. The type of sonic problem you describe ideally associated with minor clipping of sine wave. This eats dynamics and subdue phrasing. The most important is that clipping injects huge amount of HF “white” noise deluding all sound with some king of external “gray” pressure. The effect is very common when idiots run 3-8W SET and drive with them 87dB sensitive speakers. They all sound the same – “stuffy” and partially because the clipping in the wave bombard the speakers with 7, 9 and 11 harmonics at very high frequency.  I do not know if you have the same effect but from what you describe it would be what I would check first.

Romy the Cat wrote:

I do not think that you will be able to measure signal’s problem, all that you need to is to assure that your unit output proper sinusoid to full load.   I do not think that it is “noise comes through PP” and it is most likely not comes through ground. If you have the assurance that you have no Voltage clipping at full power then there is 80% of change that you PP2000 operate properly. If it runs fine from buttery then your amplification and your output filters are fine as well and then you have a legitimate case regarding the PP2000 intuit stage.

Romy the Cat wrote:

What I detected is that when the PP3000 starts and begin to charge the battery then it has very slightly different sound then what the battery is completely charged. This is acid battery as it always being charged but apparently the charging current doe has some impact to sound.

steverino wrote:

However, if I stuck the balun between the SDS and the turntable (ie the turntable plug into the balun and the balun into the SDS) then I heard noise reduction Without a negative effect on the sonics. But note that the SDS – balun – turntable motor have no direct connections with the audio components.

Lx_ wrote:

Indeed when the battery gets charged the sound is different from when it is charged. I have noticed this especially after the battery is discharged completely (after PP shuts itself down when running on battery). I think this is also true whenever after running on battery, not only after full discharge, but to a lesser extent. I have also wondered if this could explain differences in sound that I cannot explain otherwise: no other device getting on in the house, yet sound gets worse. Could it be that the PP is charging the batteries? Indeed under normal operating conditions some power must be drawn from batteries, also the batteries discharge naturally. So they must be recharged. I do not know if this is done continuously or if some discharge level must be reached before PP engages the charging circuit (which may impact sound).

So, the PurePower charging circuit is strong enough made to care the “cruse current”, or the minimal current of the fully charged battery. As the battery gets discharged then the charging circuit operates in semi-stressed mode. I did report this observation to PurePower and I did expressed my opinion to them that it is NORMAL as the typical operation of the regenerator with battery fully charged and the charger passing high current is only temporary, very short state.

However, having said above I do feel that enter charging circuitry is the biggest liability of PurePower unit and I wish they would revise it. The worsening sound during high current charge is just a symptom of much wider problem. The battery charger is the ONLY one element of PurePower that hard connects the outside line with inside line. I hope it is has galvanic decoupling of some sort (isolation transformer) but the biggest problem is that the charging circuitry creates a hell of noise inside of the units.  If you put a scope at the PurePower output then you will see a default PurePower waveform. Then, if you just put the unit in battery testing mode, what will flip unit for a few second to battery operation, than you will see as charger kicks in that over the default PurePower waveform will be a lot of distortions and they will be gradually go away as battery get charged. If you take a stethoscope and listen the PurePower chassis then you will clearly hear that the distortions on the waveforms will be very harmonious with the noise of the charging transformer (or whatever they use).

I do not know if it is unconfident filtration of charging current, the emitted EMI/RMF radiation of the charging elements or anything else but I know that it might be fixed. The PurePower needs very slightly to beef up the charging mechanism, or perhaps to unit better filtration and most likely to shield it. I am absolutely confident and I have written many time about it that the “fussiness distortions” that are not there during the battery operation and are there during the line operation are derivatives from improperly operating charging elements of PurePower. I do not know if PurePower work on it. The unit was initially designed I am sure for UPS service and those level of details were not in the mind If would not take a lot of efforts for PurePower to revise the charging elements, I hope they go there sometimes. Well, I can get from them a bypass switch for years, how long you think it will take for them to put a mu-metal shield around the battery charger?