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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.
Post Subject: Some debugging tips with PP noisePosted by Romy the Cat on: 8/31/2018
 kodomo wrote:
It is the second Romy, the noise is always present. There was always a little noise but when I had a soundsmith strain gauge system arrive, I was expecting not to have any noise. It is a hum free device. When I installed it thought, there was a buzz. I tried changing its adapters, but it was still there. After trying everything I dcided to take the pp out for the first time since I got it. The noise was gone. I started wondering if the hum from my old pre was related. I installed it back and that was very silent too. Then I noticed the faint grunge I hear from the upper mid and treble is also completely gone. It is an audible noise, it kind of buzzes, it made the phono pre hum more too. It does not matter if music is playing or not and the faint buzz does not change with the volume. The mc phono pre hum does change with volume though. Still, the same mc phono pre does not have any audible hum at the same level without pp.
Kodomo, well. I can testify that I do not have any of it. I do not think that I am deaf or that my playback is not efficient. If I had it then then I would never stop to harass Damien and Richard, presuming that PP is not operational yet or I would never use the PP. The fact that a unit in my playback introduces a known to me major auditable problem would bother me tremendously. 
 
Let clear the first perspective on the problem: it is possible that some kind unknown ether to us or to the PP manufactures problem exist in PP implementation that cause the problem. I do not mean the principle design of the unit as I do not have the problem but rather some kind of small deviation of assembly of the units that might cause the problem. This can be resolved only by PP as they need to analyses the assembling differences between my unit and the group of people who do not have the problem (I have witnessed in other people’s systems with PP a complete silence) vs the group that do have the problem. No one will be able to answer it but the PP as no one know what is the minute differences between the units. If it exists it literally might have to do with the name of the PP employee who build the unit or production run of some components of the boards.
The first perspective is most likely: I think you guys describing a normal ground loop. The ground loop is not only 60 or 120Hz even it very much might be at upper frequency and I have seen a lot of it. The good part is that it very much might be tested. I do not know the composition of you playback in elements and hos it is connected, so I will be talking about generics. 
 
Unplug every power of your playback and assemble the following: 
 
Main ->PP-> Digital Source-> Power Amplifier->Speaker 
 
In case you multi-amp use juts one upper mid channel. Place PP no closer than 6-10 feet from the playback 
 
Everything else MUST go and should not be connected nether over the power cords or over RCAs of the chain above. 
 
The PP must go to the main with ground but each single power unit you plug into PP MUST have a ground lifting cheater plug. 
 
Observe the noise you report. If it is there than unplug the Digital Source and see if the noise still there. If it is then short the power amp input RCA. If you use balance connectors then short the inputs accordingly. If you still have noise then touch your amplifier ground with you home external ground. Your amp’s ground is floating now and you might have as much as 120V between amp’s ground and earth but it should not be current in there, so it should be save to short it. Still, use a common sense and the best if you do not know what you do to short the amp’s ground and earth for the first time with a non-LED lighting bulb: if the bulb goes off then you have current. 
 
Switch the PP in buttery mode and unplug the mains. Observe what happens with the noise. 
 
Please provide a feedback of the noise is gone.

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