Well, dealing with Purepower I think it worth to understand the APS specific. They did not impress me as an engendering shop but rather they are the long-ceremony type of operation. It is not that you comment on some kind of problem on the field and then you have a guy with skills and tools on the APS side confirm the problem and provide a solution. OI did not see it in APS. From what I saw they are slow to recognize the problems and incredibly slow to react to problems. I did not see in them that “grab money and run” attitude at all.  It is understandable as they looks like do not have engendering recourses or manufacturing facilities on site and as I feel the plant the makes the Purepower generators in China does not feel that APS is the most valuable client of them. Most likely it is a very large electronic producing company in China with a lot of manufacturing inertia and APS production is just a little pimple among their production.

So, the APS interprets complains how they can, and soon or later they schedules to implement the solutions in the production runs that might e coming… next year or so. Yes, it is not very transparent operation. Add to it a relatively superficial QA from APS and you get the picture.

However, it shall not be noted that the ASP-type regenerators has some added support complexity. It is not PS Audio PowerPlant that is less sensitive to load and not Avicenna that is absolutely insensitive to load. The class D regenerator is all about the load and the reaction of the regenerator to the load. So, the APS people have much more variables to deal with in support then one might imagine.

Interesting to note that I know a few installations that use the last revision of PPP2000. Some people do report that they experience one of another type of problem. I personally have zero problems and none of the effects that Adrian, JP and other report. We do have the same vintage of regenerators, so there are possibilities:

1)      My and your PP200 are in fact NOT the same

2)      There is something in my and you systems that make PP2000 to operate differently in my and your case.

I do not know the answers and frankly since I have none of the problems I do not particularly care to learn how to get one. If you do have problems then I would suggest taking a bit more proactive position then just a send then a few emails. You need to call them, call them again and to demand a satisfaction. Since you do not ask for anything else then a proper operation of your units then I do not call it harassment but rather your desire to get what you shell be given. I did not detect that APS people were overly frustrated with my complains or concerns as they were always back up with facts and they always engaged in the conversation about the problems. The result is different thing – you might wait but at least you have a record that you did complained during your warranty and you have a promises that it will be addressed in a week, month or year – the due date will be blown but they will sloooooowlwy look into the problems. Do call them again and remind that the problems are still not resolved, after all you need to address the problem more then they need to do it.

What I think APS need at this point is some kind of official public position regarding to what they do and a public knowledge based facility what user would self-debug own problems. I think they need to put a collaborative site out with support forum and KB. It would address all concerns and would prevent people runs across the various sites and to pick rumors. I have no idea why APS did not take yet as official stand regarding the stability of own products.

Yes, of course.  And since we are supposed to be educated and sophistocated people here, you might thnk we'd have recognized and prepared for all this ourselves, before forking over $3k for "results".

But the Fact is that many of us are so sick of the Bad Electricity Problem that we have gone soft on the idea of an easy fix, despite strong evidence to the contrary.  Furthermore, APS knows it, and they work the angle, just like all the other sheisters.

Although I have [barely] managed to restrain myself from sending them money so far, I have done some reconnoissance.  Just from talking to them and from the steady negative feedback, I know that APS are far more concerned with marketing, selling, producing and shipping units than they are with anything as abstract as actually solving the BEP on any tangible level, as far as any given end user might be concerned.  Ironically, you might have a better chance getting hum fixed than you would getting the thing to correct BEP, if that turns out to be a problem at any point.

As to how long it might take them to make good on problems in "the field", I am guessing they will start getting around to that if they think it's hurting (or threatening) the bottom line, IF they still have the capital reserves at that time to launch a rescue mission.  Again: this is where the Mk II, SE usually comes in...

Best case in terms of "intentions", the concern is always that they will "intend" to address problems for a while, then just give up when it finally becomes ovrwhelming.

And there is really no sense in citing "customer satisfaction" as proof of QC (QA, these days, I suppose), since the broad swath of their market will always be Morons, anyway.  They either have it in them to do it right, or they are incompetent fuck-ups; or they are pirates.

Paul S

drdna wrote:

After many unanswered e-mails, I got word from APS today, who said they have had a few customers with similar issues and that it seems to be system dependent. However, they also said that they were working on a way to fix this that they might have in as soon as a few weeks and that they will not charge anything to any customers to make the necessary corrections. Well, okay, we will see.

Do we finally understand what part of the Bad Electricity problems is [broadband] noise and what part is related to "waveform" issues, such as phase?  And do we understand how attempts to deal with either one of these issues might affect the other?

I ask because I have never seen a single corrective device that offers balanced, quiet, phase-perfect power.  By "balanced" in this case, I mean that the nueutral/ground is isolated and re-referenced at -60V, while the hot leg is set at at +60V, in  the case of 120V AC.

Neither have I seen a full-on "regenerator" that does not employ a digitally-synthesized reference for the reconstruction/propagation of its "perfect" sine waves.  Sorry, but I just don't get how this could stay clear of its own noise.

I would not be bringing this up again if it looked like the PP2000 neutral/ground was actually isolated.  Obviously, if you unplug the thing, then its ground just "floats".  But even in this case, cross-contamination from the loads appears to be possible; likely, even.

Paul S

Paul S wrote:

I ask because I have never seen a single corrective device that offers balanced, quiet, phase-perfect power.  By "balanced" in this case, I mean that the nueutral/ground is isolated and re-referenced at -60V, while the hot leg is set at at +60V, in  the case of 120V AC. Neither have I seen a full-on "regenerator" that does not employ a digitally-synthesized reference for the reconstruction/propagation of its "perfect" sine waves.  Sorry, but I just don't get how this could stay clear of its own noise.

Paul S wrote:

I would not be bringing this up again if it looked like the PP2000 neutral/ground was actually isolated.  Obviously, if you unplug the thing, then its ground just "floats".  But even in this case, cross-contamination from the loads appears to be possible; likely, even.

What I have is a subwoofer made by ACI; no information on the amplifier used other than it uses a two prong power cord, no ground.   When I hooked it up to the APS 2000 I got a very loud pitched hum.  Taking if off the 2000 and plugging it into a wall outlet on a different circuit, I still got the hum, but not so loud or high pitched.  Any ideas as to what is causing this both directly hooked up to the 2000 and then only hooked up by way of a subwoofer pre-amp output from the Pioneer Elite Receiver.   The sub is used for HT, which in most cases would drown out the hum.   However with the new sound formats being used by blu-ray you can get sound quality for music that rivals CDs.   If this hum comes through on a quiet passage in a BD concert...well, I'm afraid the unit will receive a "not ready for prime time rating" for me.   I am in process of doing a review on the 2000, and so far the only feedback I'm getting is; from ACI why mess with something that works fine without a power reconditioner.   From our friends at APS take the PC equipment offline from your audio equipment.   This had no effect on the hum.   So, my next option would be as the manual states, use the adjustible circuit that removes hum in torroidal transformers of certain designs.   I did a review on the 1050 which received high praise from me as it solved a tube amplifier problem that could have cost me thousands in burnt tubes and who knows what damage to the mono amps.   I now use a Pioneer Elite Receiver; whigh is the only difference between then and now; that and the location of the house; the ACI subwoofer was in my system at the time of the 1050 review.  So why this change? 

Beav wrote:

What I have is a subwoofer made by ACI; no information on the amplifier used other than it uses a two prong power cord, no ground.   When I hooked it up to the APS 2000 I got a very loud pitched hum.  Taking if off the 2000 and plugging it into a wall outlet on a different circuit, I still got the hum, but not so loud or high pitched.  Any ideas as to what is causing this both directly hooked up to the 2000 and then only hooked up by way of a subwoofer pre-amp output from the Pioneer Elite Receiver.   The sub is used for HT, which in most cases would drown out the hum.   However with the new sound formats being used by blu-ray you can get sound quality for music that rivals CDs.   If this hum comes through on a quiet passage in a BD concert...well, I'm afraid the unit will receive a "not ready for prime time rating" for me.   I am in process of doing a review on the 2000, and so far the only feedback I'm getting is; from ACI why mess with something that works fine without a power reconditioner.   From our friends at APS take the PC equipment offline from your audio equipment.   This had no effect on the hum.   So, my next option would be as the manual states, use the adjustible circuit that removes hum in torroidal transformers of certain designs.   I did a review on the 1050 which received high praise from me as it solved a tube amplifier problem that could have cost me thousands in burnt tubes and who knows what damage to the mono amps.   I now use a Pioneer Elite Receiver; whigh is the only difference between then and now; that and the location of the house; the ACI subwoofer was in my system at the time of the 1050 review.  So why this change?

 The “hum” might be from various reasons. If you imply the 60Hz and 120Hz then it most likely some odd ground loops that in case of PP2000 are more complicated. It need to be know if the hum you described is not mechanical nature, what kind it is, how it relates to volume…. the regular things. What surprised me that if people have ground loops with records cartridges then they fight the loops but what they have the same proboems with AC lines then they feel that it is much different…

Actually, Beav, there is something different in your case. I think what you do it wrong. If you are a reviewer and you are in possess of writing a review about the PP2000 then I would advise you do not search online what others say but subject of your review but you your own mind. If you have any technical or exploiting difficulties then take it to the PurePower people as the observation of their compliance to your problems shall be a part of your review as well. I know that many of the audio “reviewers” write their semi-idiotic observation by browsing web and snatching the phrases and opinions from here and there.  I do not think that you would do a good service to your or other is you practice it.

So, if you are in possesses of writing a review then you shell not read this thread and shell not ask questions. Your job is to provide answers or to sharpening the questions…

Actually, Beav, there is something different in your case. I think what you do it wrong. If you are a reviewer and you are in possess of writing a review about the PP2000 then I would advise you do not search online what others say but subject of your review but you your own mind. If you have any technical or exploiting difficulties then take it to the PurePower people as the observation of their compliance to your problems shall be a part of your review as well. I know that many of the audio “reviewers” write their semi-idiotic observation by browsing web and snatching the phrases and opinions from here and there.  I do not think that you would do a good service to your or other is you practice it.

The Swiss dealer is capable of replacing your failed MB with a new non suceptible board - just email me richard@purepoweraps.com and I'll arrange parts supply. We also have a Europe service facility in Germany.

Hum is a multi faceted problem. We have identified 4 completely different causes of hum in amplifier power supply transformers exacerabted by AC power problems - and that kind of hum is not even the most common hum audiophiles have to deal with. The no 1 cause is ground loops in interconnects - which is outside our purvue. PurePower can effectively eliminate amplifier transformer hum from AC power supply causes - including DC offset, asymetrical voltage waveform (sometimes called virtual offset), common mode noise from faulty grounds and current waveform anomalies caused by asymetric current draw by amplifier power supplies.
All of these hums are distinct from hums entering the signal path and emanating in the speakers - this is mostly unrelated to AC power issues and again outside PurePower's purvue.

If anyone is waiting for a PurePower technical solution to amplifier transformer hum then please email me with details. We can help with these. richard@purepoweraps.com