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 Romy the Cat wrote: |
| This morning I was listening Messiaen’s Tarantella-Symphony powering system from the bare AC lines. It was far from the sound I would like to have and I decided one more time to insult myself with PP2000. This time I decided to take another PP2000 unit. To my surprise Sound was not right but it was different result then I had the whole week. That picked my curiosity and let me for a couple hours marathon of re-listening all 3 of my PP2000 regenerators.
To my surprise, pleasure and horror they all turned out to be absolutely differently sounding. PP2000 #1. This one that has been using all week - the updated my old PP2000 (new version of motherboard). This one the absolutely worst – large amount of unpleasant noise, hugely homogenized tone, no bass, no anything – just disaster. It runs fine on batteries with fine sound. This unit I did some very basic measurement and they were fine. PP2000 #2. I do not get this unit. It does much less, practically no noise and no homogenization. It has some bass and in a way a clear bass. But something is very wrong in this sound, I can’t figure out what. It runs not identical but similar from buttery. I have no idea what is wrong with it, I did not measure it and I prefer do not use it. PP2000 #3. This is a lucky bustard. It has practically no noise, no homogenization and it highlights the tones almost as good as my old PP2000 did. It has that precision, discrimination and authority in tonal and dynamic accents for which I so love the PP2000. It has a bit too shallow very lower bass and a bit general brightness that I did not remember the old unit had. It is not a lot but it there. It runs from buttery a very slightly better – picking the lower bass in partially getting rid of the business at HF. The way how this unit sound from butteries is how the properly functioning PP2000 shall sound. The PP2000 #3 I think is useable, the first two units I am afraid not. I would like to have my old PP2000 back then I will have 2 find sounding PP2000 hopefully if PurePower will fix whatever is wrong with the new revision then I will get my third unit. Since the all so not even it is possible that the secret in some kind of calibration or adjustment that might be not done properly at PurePower. I did ask multiple times before they shipped them if the tested them and they told that they did. I did not measure my PP2000 #2 and PP2000 #3 but even my worst PP2000 (#1) measures fine. So, go figures that are responsible for sound in those units. If PurePower have more interest about subject of good sound and how to get it predictable then the situation might be a great opportunity to learn about it. Unfortunately it looks that PurePower more care about damage management. Boring and contra-productive. |
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OK, now the situation clearer a bit. Last night I listened my 3 PurePower 2000 units, my analyses of this sound is in the post above. This morning I measured them and put everything in perspective.A few words before I lay down the facts. Over the last week I got a number of signals from PurePower that I shall not defame their products. Their marketing director Bob Rapoport – a certifiable idiots – informed me that my finding about PurePower 2000 are “based on sheer fantasy”, that he “would bet that in a double blind AB test I would never know the difference” and that I shall “take down the entire thread about PurePower
from your blog” because it “this is a hobby to you, but its my livelihood”. Their technical people dodge my calls. They claims that they here no difference of any kind between old and new units and between PP2000 running from AC and buttery. This is very alarming and my odder to demonstrate it to them, even more - my proposal to give my facility and my engineering rescores for their disposal to find the problem – all left without answer. The PurePower owner has, who looks like offsite now days, has more rational position. He also is concern about me “defaming” his company product. He diplomatically implies that “we are interested is solving your problem”, which makes me surprised: my problems? Really?
The whole point is that the problem I am experiencing is not my problems but purely the PurePower, or more accurately the problems with PurePower 2000 operation.
Think logically: even if I was some kind of idiot and was absolutely misused the PP2000 then how this might explain that rotating PP2000 units in absolutely the same connecting and loading configuration produce 3 drastically different results from absolute garbage to near acceptable, still none of them produce good result as it was with former production run. Even with my presumption of my partial deafness the logic would suggest that something is not right but not with me but with the regenerators. Ironically, no one before noted that my comments about the PP2000 were inaccurate, quite in contrary.
The most important thing is that what interests I have to report negatively about the PurePower units? The whole point of my report and my journey for a proper power device is that it is not exposed to any agenda, to any respect or disrespect to anything, even foe my own observation. The only mental schema I have is to find a devise that would produce the best good for Sound electricity. If it affects somebody sales number in negative or positive way then I do not really care and I am absolutely blind to those facts.
Anyhow, as I said above I think I know what the problem the new PP2000 might have. Well, it is not knowledge but rather guess. Let me to present the facts, you make your own concussions.
First let talk about the PP2000 #3. The one that has the best sound among my 3 units. It does NOT sound right – it way brighter than the older PP2000 was but it is semi-usable as a temporary solution, contrary to the rest of my PP2000. Let compare the new PP2000 #3 with my old PP2000.
Here are both of them running from AC (revision 2008 first, then 2010)
Then here are both of them running from butteries (revision 2008 first, then 2010)
In all cases they are loaded to the very same load. We can clearly see that the buttery operation is virtually identical and sonically they are in my view are identical as well. The AC operation has some a few kHz noise injected into 60Hz cycle something that I two years back called “fuzziness”. If we compare the 2008 and 2010 fuzziness then it is very obvious that that the 2010 fuzziness is MUCH better lover amplitude, even spread across wider area. So, of the PP revision of 2010 is so much better than rev. 2008 then why the rev. 2010 sonically so bright?
To understand the answers to this question you need to understand one of the main consents of my audio believe, something that I very aggressively use foe my playback design. Facts are not causality, fact are juts outcomes presented to the realm of know. If distortions are facts then we do not hear distortion but we hear the mechanisms that course the distortions. We do not fight with distortions as they are irrelevant. However, by tuning and fixing the poisoning effects that cause the distortions we affect true results. So, it is obvious that some of noise coming through the regenerator, it might be AC noise of it might be (and most likely) the PP2000’s own noise affect the unit output. How can we say that this affect is negative if in 2008 it has very minor (if any) negative effect to sound and in 2010 the sound is much worth but the measurable output noise is much less? Again, “we do not hear distortion but we hear the mechanisms that course the distortions”. We need to find the mechanism that creates those distortions. If we do then we will have answer that we are looking for. The guess of my engineers to whom I asked this question was that DC-DC converter (that does not work when unit runs from buttery) produce some ground, or air or some kind of other noise (that all packed in the box very tight) that penetrate the output stage of final amp or the oscillator circuit. It looks like DC-DC converter that bust 72V battery to 165V, the oscillating circuit and the output stages are fine but as soon the DC-DC converter drive voltage to 72 and rectifiers are activated they somehow leak noise output stages.
OK, let talk about the PP2000 #2. This is the unit sound of which I did not like last night as was not able to figure out what I did not like. This is pure BS, sorry PurePower people but you absolutely shall not be doing this. The negate wave of the sinusoid is horizontally clipped, which is an indication that the internal amp runs at unofficial voltage. The DC offset regulator can change the depth of the clipping but it is not able to eliminate it. Also, the entire sinusoid is very shaky, as I look at the scope it trembles like at the time of earthquake. Something is very mis-regulated with this unit and in my mind it shall not be ships out to customer. Interesting that nowadays the PurePower regenerators are shipped with certificates of testing. I did not even look at them as I am convinced that they are fine. So, ether PurePower fakes the resting results or then test wrong things. How else one would explain that a unit with clipped wave would be send out to the field.
The OK, let talk about the PP2000 #1. This is absolute mystery. It has virtually the same output and the same wave as the PP2000 #3 but absolutely different sound. This type of the thing MUST be researched in order to fine the prime what makes electricity to sound bad. That is execrably what I would like PurePower to do. Let pretend that I use too slow scope and juts do not see the UHF oscillations. Let pretend that rectifiers produce switching noise (and this thing goes across anything) that got some penetration to inputs of the class D amps and shaking by feedback the whole output stage is in 700-800kH oscillations. Did you see how oscillations in high mu tubes kills all sound, might it be something like this in PP2000? Absolutely, it might be anything! And this searching for this “something” shall be what PurePower shall de and do not blame the whistle blowers that they “slandered my product in a public forum for no good reason except your mis-diagnosis and rush to judgement”. Frankly speaking I am very much offended with this feedbag. I was under impression that my and PurePower goals are the same – to have better devise to deal with electricity problems. If PurePower would claim innocents but the fact that they sold 100s of those units and everyone love them then it: 1) would not fly in my books 2) not true. I can continue this explanation if PurePower insists.
Anyhow, I still am waiting for the PurePower response. It is very possible that there is no design true difference between PP2000 from 2008 and PP2000 from 2010. The differences in sound might be explained by “normal” production differences of PP2000 units. PurePower need to found out what is responsible for of their regenerator Sound and learn how to calibrate PP2000 in order it has default sonic characteristic. The do NOT do it now and it looks like sonic performance of their units are absolutely random.
In the end I need to say that I am tired from this whole situation I am tired deal with company where customers want better and more stable resets then manufactures can furnish. I still feel that USP devise with class D amps made specifically for audio purpose is the way to go but at this point if I know another alternative of the same product then I would try it. The PurePower is very close to where they need to be – their PP2000 DC operation is the ultimate that answers all questions. They are so close from having the “right product” but they do not make the final move. I have no idea what they behave in this way. A good consultant-designer would within a few weeks find all design and technological problems that might PP2000 and devise a set of calibration and testing procedures. Why PurePower does not go this way? Because the people stupid enough to be satisfied by random results? Well, I do not.
Rgs, Romy the Cat
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche