How noisy is my line? Audio Prism Noise Sniffer

Audio electronics do not run on 110 volts AC. They run on DC from 5 volts on up. The job of any well designed power supply is to filter out all AC and regulate the supplied DC voltage accurately.  If any "noise" (which is AC) gets through sell it and get a piece with a decent power supply. 

Having said that there are instances were filtering can make a difference. As an example, the high voltage power supplies that charge the diaphragm of electrostatic loudspeakers is very simple. There is no current involved. It uses a step up transformer to get to 250 volts AC then a voltage amplifier of serial diodes and caps to get to 6000 volts. Any noise online might be amplified in the process and affect the diaphragm's performance. 

@panzrwagn  Do you know of any digital scopes with really easy to use/nice to use spectrum analyzers?  When I last had one the spectrum analyzer was a real chore to use, so hard to evaluate the types of noise I was looking at.

@eric_squires Any test test equipment that provides quantitative data will require some degree of technical capability by the user, but I agree, many do require a little too much Electrical Engineering background, not to mention significant capital outlay.

Take a look at this software only package though, 

You'll need an interface like a Focusrite Solo or 2i2 and a patch cable for line level use or calibrated mic (or calibrated USB Mic

 for speaker measuring only) 

Or, to get started for free, download the Spectroid app for free.

Brief report.

Electrical Experiments using Entech Sniffer

Interesting experiment: 
1. Put noise sniffer into raw outlet usually occupied by my Audience Adept and rest of gear.
2. Positioned laptop next to meter with live zoom feed to my phone.
3. Went to nearly every single thing on the same line as that outlet and plugged and unplugged it. Watched zoom feed on from my laptop on my phone.
4. Some things had no effect on reading. Some made it noiser by 3-5 increments; some made it quieter by 3-7 increments.

Interim hypothesis: leaving those things on upstairs might make my audio background quieter. Hmmm.  But since that's not how I listen, I plugged everything back in.

Trying again, this time with everything into my strip, with the Entech in there, too. 

5. Plugged in Audience and rest of rig. Plugged sniffer into the power strip they are plugged into (which has a Venom Defender in there, too.)
6. Repeated all the pluggings and unpluggings listed above in (3.)

Result: no change made any difference at all. None.

Ultimately, my Audience Adept r2r makes a difference according to this sniffer. The Audience drops the reading by 30 points so and adding the the Venom Defender into the strip drops it another 12%.