Evaluating Equipment-induced EMI noise in one’s audio system


Audiophiles have long recognized power line noise as the bane towards enjoying one’s audio system since at least the 1970’s (if not earlier). Folks appreciate their rigs often when the power grid has lower traffic during off-peak hours, such as late into the evening. More recently, perhaps beginning in the mid-1980’s or so (please don’t hold me to dates here, as I’ll stipulate I might be off on time), audiophiles have employed numerous devices such as power conditioners, power line filters, power regenerative devices, even battery-driven gear as a way to reduce power line noise getting into one’s system. And many of these devices actually work as claimed. But in this thread. I want to explore the extent to which the audio equipment, itself, whether a power line noise treatment device or an essential or auxiliary piece of audio electronics component introduces EMI or RFI noise into one’s system. I’ll describe a simple, inexpensive tool and method to evaluate any component’s inherent line noise. And whether one should use that as a guide to accept or reject a given audio component in one’s system. I will present my findings for two well known components familiar to most folks here in the forum. One will be a power conditioner that regenerates a corrected AC power signal. The second component will be a Class D amplifier and external power supply. Buckle up and let’s have some fun! 

128x128celander

@steakster I agree with everything you said in your recent post. I also don’t listen to my system with a TriField EMI measuring device. But I’m finding it as a useful tool to quickly decide whether a given component contributes significant EMI noise to the power line of the audio system. What remains to be assessed is the correlation of EMI noise to audible discernment of sound quality degradation as a result. 

Put a piece of shungite near the wall plug and measure it ...Cover the power supply with a plate of shungite...Neasure before and after ... Have fun...

Just a test... 😊

Merry Christmas to you and your family... 🎄

 
 

 

 

And then there’s the path from power to signal path, and sources power supply vs environmental RFI, vs AC power supply. And individual parts EMI generation. Rather complex issues and measurement problems to be identified prioritised and solved.