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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.

Post Subject: PP3000+ and ... the alien switching forces.Posted by Romy the Cat on: 8/21/2014

I have written in past that for some mystery reasons my PP3000+, and I presume all other PP3000+, do adversely affected by switching power supplies in the feeding line. I have PP3000+ and older PP3000 and both of them works wonderfully, one on main listening room and another in opera room. However, if they work at the SAME time then they do compromise each other and sound become very auditably brighter. That is what I am saying for a while but recently I discover something more.

The presence of any switching PS on the same line where my PP3000+ sits does contribute negatively to sound. That is despite that my PP3000+ connected to a dedicated line, the switching PS on the same half of 220V still reaches PP somehow. The degree is much less but auditable. For instance I use powerful portable workstation Lenovo laptops, the W series , and they have big 160W power supplies. I usually do not that I plug them and did not file then they affect sound. However, a few days back I was listening my Wagenseil's quartets for low strings and suddenly felt that sound is unreasonably muddy and bright at the same time. In those quartets viola plays upper octave lead but it had no typical for viola dark sound but rather it was too cheerful. I was walking around the playback, scratching my back and was not able to figure out what was going on. Then I felt that sound become softer and viola got darker. What was going on I was wondering...

I sat to my chair, took my laptop to write some email and then it hit me: the laptop's PS was very hot. The point is that I left the laptop on the deck a day before and the big 9-cell battery was almost completely discharged. As I plug the laptop to PS the charger detected the ultra low impedance of discharged butter and begin rush a lot of current across PS, presumably injecting a lot of switching supply noise to the mains. Well I tested the theory. I have discharged another battery and did again the experiment. Sure, it was clearly auditable from 5% of battery change to approximately 15-20% and after which I did not think I felt any difference.

I have absolutely no explanation of the phenomena as PP3000+ flats the things to DC not to mention it dissecting main by 20kHz of own switching sampling rate. Anyhow, watch any switching PS in the line where your PP install. The effect might be minor but it is there.

Rgs,
Romy teh Cat

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