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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.
Post Subject: Still fightingPosted by N-set on: 11/24/2020
My exorcisms to eliminate 100Hz PP induced noise in the EndOfLife phono gave no results so far.
- I took GND from the PP socket and tried connecting it to various GND points I could access (the signal GND plane, input sockets GND, the case). This only increased the noise.
- I tried connecting different GND points within the circuit. No results.
- The noise seems larger when the PP batteries are not 100% charged, suggesting it comes from the charger working (it disappears when the PP is in the battery mode)
- On the SUT inputs, the noise changes its amplitude with changing the orientation of the signal unit with respect to the power supply but never vanishes completely.
The last makes me suspect it might be emitted by the phono power supply and travel by the air to the signal unit. Perhaps PP excites the supply big chokes? But then why lifting the phono ground from the PurePower eliminates the noise completely?? Cannot understand it. Will get a scope tomorrow and try seeing where the noise enters.
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