floobydust wrote:

one can identify multiple devices that provide clean power without impacting the sound quality then thru some level of analysis

floobydust wrote:

what effect do transient load changes have on the voltage output and waveform...

floobydust wrote:

AC power has but a few simple parameters: 1- voltage, 2- frequency and 3- waveform.

Jp,

I do not understand what you report and what Adrian repot. Is your “noticeable ever-present buzz” coming from loudspeakers (I mean is it acoustic noise) or is it a mechanical noise that coming from regenerator and it comes from your component plagued into the regenerator. In first case it ground loop, in second it is DC component. What does it mean “directly in the listening field? Doe it fluctuate with volume? Does it changed with lifting ground on regenerator load? Dose it change with change of sources? Did you measure the DC on the regenerator output? Did you try to run the regenerator’s load via isolation transformer? I mean it is strange to me that you report the buzz it as it something “minor”. If I have this problem I would toss anything the does it out of my house. I think you need to be more specific with what exactly you experience and then you will easily identify and perhaps resolve it.

Romy the Cat wrote:

Is your “noticeable ever-present buzz” coming from loudspeakers (I mean is it acoustic noise) or is it a mechanical noise that coming from regenerator and it comes from your component plagued into the regenerator. In first case it ground loop, in second it is DC component. What does it mean “directly in the listening field? Doe it fluctuate with volume? Does it changed with lifting ground on regenerator load? Dose it change with change of sources?

drdna wrote:

I am quite sure it is a ground issue, as it is noise coming from the loudspeakers regardless of source or volume. Lifting the grounds on the amplifiers… eliminates the problem.

floobydust wrote:

By definition and code, a separate non-current carrying ground is required for all outlets. In every house I've lived in, the ground is a separate thick copper bar that goes deep into the ground (the earth outside the house) and that is the ground connection for the house electric system. How can this can be considered dirty, other than the dirt that the copper bar is earthed in?

You are kindling right? The problem with grid ground is that is shred with anyone on world. Well anyone in the world is not a big deal your neighbors is truly a big deal. The grid’s ground provides a return path for fault currents, so it your neighbor has a leaky circuit then you have it. All capacitive drifting of your neighbors you would share with them if they are closer to the grounding point then you – in a city what assurance you have? Any single impulse PS (including the PP2000) in any single computer of any other devise return a tremendous amount of dirt to ground – it is great if it have the path to Earth right there but in busy neighborhood it is not the case. Are you sure that your ground impedance is lover then the girl who below you uses an espresso machine and hair fan? Did you measure the impedance of ground in a regular public building? In the best case it will be sitting in the cold pipe and you can to 10 time lower impedance with your own properly driven into alkalined Erath rod. The point that I am trying to make is that common ground of public grid is public sewer the only defense for you to have lower ground impedance than anyone else. But it is not a defense but minimization of damage, the true defense is in my view is do not use pubic ground but use your own if you like me live in a center of city, like I do. When use my own ground then I always (!!!) had voltage between common public ground and my own ground (15 feet copper rod driver in pretreated backyard and 8Ga 30 feet cable from chassis of single-ended preamp which was is the only contact point with ground in my system).

The Cat

Paul S wrote:

Truly desperate scofflaws might find themselves so annoyed by the hum that they lift the PP2000 AC ground connection at the PP2000 chassis and run that unit's ground only to a dedicated ground (with a lower impedance, of course), instead.  If you have hum but no dedicated ground line, then put in a dedicated ground line before you post again, please. Again, don't try this at home, whatever you do!

The PP2000 has nothing to ground – it is juts shorted and the hum people apparently pick their own ground loops that too masked in noise without PP2000 (juts a hypnotizes). Running the system with own separated ground and PP2000 I find is less preferable, at least in my case as the idiosyncrasies of voltage between neutral and ground are VERY inflectional when the PP2000 is used. I personally plug everything into PP2000, using effectively the dirty common ground and then wherever it necessary in my playback I lift ground on individual components in order to break the loops.  I found that having a ground that referenced outside of the PP2000 was more devastating to sound then the use of common ground from the wall.

Paul S wrote:

I bid Good Luck (and Good Night) to anyone who is especially content with the good electricity, in and of itself, and I dismiss anything like object worship of any product.  It's a hunk of metal, boys, that's all; and if APS are not lucky clowns, then they may not be good people.  Caveat.

Paul, I am not sure where you see “worshiping of any product”, I think you get the things wrongly. When did you last time bitch about the bad electricity?  I did in the end of December… I very much do not saddest you to try the PP2000, I would like you to try something else – maybe you found something better and I will learn. The point I am trying to make that you made a numbers of comments about PP2000 that I am not sure that they relate to any reality that I am experiencing with this regenerator. I am not in a business to worship power devises – I am in a “business” to identify and to address the specific problems that I face. I very much glad that PP2000 reduced the sharpness of my electricity problems. Worshiping? I think that it is your perception but not my expression.

Romy the Cat wrote:

the hum people apparently pick their own ground loops that too masked in noise without PP2000.

Paul S wrote:

I bid Good Luck (and Good Night) to anyone who is especially content with the good electricity

drdna wrote:

It is not exactly correct. There is 60 Hz hum eliminated by lifting the ground to the amplifiers. The neutral is connected to the ground prong and chassis in the amps, so I assume it is setting up a loop. However, there is a second problem of higher frequency hum which is eliminated only when the PP2000 is unplugged from the wall and runs from the battery. I think my thought would be if there is some way to treat the AC power input to the PP2000 to eliminate the second hum.

The “higher frequency hum” is most likely the 120Hz hum or the hum that is coming from full wave rectifiers of your amp. It is not the problem of the PS itself but the PS in context of particular grounding schema. When a PP2000 is unplugged from the wall and runs from the battery it is not that PP2000 is unplugged but the ground via PP2000 is unplugged.  You most likely have no noise because you have another path to ground and your system is perfectly grounded. When you introduce the PP2000 you introduce juts another path to ground. I still do not feel that it is PP2000 related. You can very easy to measure if your PP2000 shorts the ground – it shell be 0R from PP2000 ground input to output.  Then you would need to find what create the loop. There are two ways to do it. First way is shorting the loops with a shorting cable that you need to bridge different ground points. With some proactive it could be very handy. The simpler way is to plug juts one amp one speaker and one souse into the same power stir (or PP2000), get no noise operation and them add one element per time and to see when the hum show up.

drdna wrote:

The sounds continue to change from day to day.

Romy the Cat wrote:

When a PP2000 is unplugged from the wall and runs from the battery it is not that PP2000 is unplugged but the ground via PP2000 is unplugged. You most likely have no noise because you have another path to ground and your system is perfectly grounded.

Romy the Cat wrote:

When you introduce the PP2000 you introduce juts another path to ground.

Romy the Cat wrote:

The simpler way is to plug juts one amp one speaker and one souse into the same power stir (or PP2000), get no noise operation and them add one element per time and to see when the hum show up.

drdna wrote:

Yes, I assume the problem was the ground path through neutral, either because of a high impedance or because of an interaction of the PP2000 with the isolation transformer.

Ah, you have also an isolation transformer sitting in the system? Where does it sit and what it does?

drdna wrote:

But if everything is plugged into the PP2000 and the PP2000 is unplugged, nothing is connected to the wall. It just loses the reference to the additional ground of the neutral AC path?

A presence of one single reference to ground is the same as having no references to ground from the hum perspective. You will have a noise if you have more than one references to ground. You can easy test it by lifting ground from PP2000 input. It would not be a good way to operate but as the hum-test it will do.

drdna wrote:

Well, I tried this first and the hum was always there unless the PP2000 was unplugged.

Adrian, I still do not see how it might be PP2000 related and I have no idea why you lifting the PP2000 output still, as you report,  it has the hum. It just does not makes since to me.

Romy the Cat wrote:

You will have a noise if you have more than one references to ground. You can easy test it by lifting ground from PP2000 input. It would not be a good way to operate but as the hum-test it will do.

Romy the Cat wrote:

I still do not see how it might be PP2000 related and I have no idea why you lifting the PP2000 output still, as you report, it has the hum. It just does not makes since to me.