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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.
Post Subject: Again, how it works in my case.Posted by Romy the Cat on: 11/8/2020
 steverino wrote:
Later after the PP battery was replaced hum disappeared forever.

Interesting. What made you to replace the battery? The reasons I ask is a because an old buttery would not be different for powers supply then new one. They both would have near null impedance. What I presume that during the battery replacement you physically stressed the unit and whatever problem was inside was gone. Generally to argue the reason why it is creates the noise is a moot point as we have no assurance of the PP stability of operation from unit to unit. It might be that there is some unit out there that are faulty in term of noise or might be using a faulty part. Of coil that work in pulse mode has no shielding then it will throw a lot of noise in air.  With QA control that we have with PP everything is possible. As many unit I had I did not have any noise problem that I was not able to address by moving the unit further. As least it what I remember now.
 N-set wrote:
Romy, do you power your End of Life phono from the PP?? 

I have the same phono, with choke input PS for both the heating and the HV. 

1) If I plug the phono just to the wall, the noise just normal with PP operating Online some 2.5m away. Noise ok, no problems.

2) If I plug the phono to the PP at the same physical separation of 2.5m, all kind of hell breaks loose. Below is the spectrum of the phono output (with a shielded AC cable and PP in the Online mode). Switching PP to the battery operation lowers the noise practically to the normal level, but it's good only for 15mins of operation. 

So does Gold PP1500 does not want to work with choke input PS, like the first unit Romy tested?? 

Other minor thing - with completely no load (everything unplugged), the load indicator bar is always showing the minimal 25% load? Normal with Gold units? 

Yes, I have everything is plug into PP, including the End of Life phono. I do not know how the load indicator works. In my case all units did showing 0 to 100% looks like accurately. Regarding the noise. What does it mean “good only for 15mins of operation” what happening after 15 mins?  The 2.5m away is plenty far away and you should not have a problem. The choke input PS is not a problem also.  Most likely you have some kind of not detected yet ground loop. The phono and computer are typical suspects. I have once a lop over a computer monitor and once over the computer routing switch. Even now I have a very minor ground loop that is very clearly auditable of I touch anything metal at my TT. It is possible to deal with it but I do not pay attention to it as it is completely silent when I do not touch any TT metal parks.
So, again. Plug PP into wall, inside the ground. Do NOT list the ground on PP power cord. Plug an extension cord with splitter into PP, listed the ground on the splitter. Plug one by one your components into the splitter. If you detect the noise, then lift the ground on the offending component. If you can not then begin to lift the ground on the components that looks like not the cause the noise. In my case all my components are connected into PP and EACH of them have ground lifted. If I do not use the ground lifting adaptor, then I juts break away the ground pin on the power cords. Remember that in your system all components are connected with RCA ground terminal, so the ground in PPs is just a second pass and an opportunity to a ground loop. You should have playback components to be connected with one single ground point, the RCA jack is the best location to it. So, in my case my components have no ground at all in reference to PP or to wall. I think I have a few dozen volts between the ground of my components and the wall ground. It is not a big deal as it is stray voltage with no current. I do not touch the house pipes and TT tonearm at the same time? If I would like to be safe, then I might just run a single ground cable from a single ground point from my ungrounded playback to a poll in backyard. I do not do it now as in my current listening room there is nothing that connected to main ground.  Problem not the best from a person who have 3 small kids, but we are taking about ground loops now.

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