Dirty Power

[Patrice B]

There's a lot of work that goes along with designing switchmode power supplies for audio applications. The noise is not dumped indiscriminately anywhere, not if you want your product to be quiet and also pass EMC regulations. The current is carefully steered away from sensitive paths so as not to corrupt the noise floor.


Line frequency transformers can certainly radiate EMF that will not be blocked by copper tape or paint. The best thing to do is put some distance between the offending transformer and the pickup/bass. Shielding against low frequency radiated noise can be done, but it gets expensive in a hurry.

The most distance I can put is already maxed. The transformer is probably 40-50 ft behind the house so I guess the exact position I should use is tied to the interferences it emits. I would just have to bring the bass at school to verify if I have to put it in a particular orientation too.

**… or build a Faraday cage around the studio .

Could it also be the main electrical panel not too far away from the home studio in the basement?

 

[agedhorse]

Could it also be the main electrical panel not too far away from the home studio in the basement?

Probably not.

 

[beans-on-toast]

The most distance I can put is already maxed. The transformer is probably 40-50 ft behind the house so I guess the exact position I should use is tied to the interferences it emits. I would just have to bring the bass at school to verify if I have to put it in a particular orientation too.

**… or build a Faraday cage around the studio .

Could it also be the main electrical panel not too far away from the home studio in the basement?

A noisy power transformer on the pole is something that they can fix, if they want to. QRM is man made noise.

 

[Patrice B]

A noisy power transformer on the pole is something that they can fix, if they want to. QRM is man made noise.

How do I know if the xformer on the pole has something to do with induced noise in my pickups/basses? Any way or app to monitor?

 

[Patrice B]

QRM/RFI tracing, out of my skills:

 

[Patrice B]

QRM sniffer:

 

[agedhorse]

Noise due to high voltage discharge is both radiated and conducted.

 

[Patrice B]

Well, after further investigation: single coils - Jazz with only one pickup dimed, Gretsch Junior Jet, PJ’s with blend of P and J - has to be played in the perfect orientation. Humbuckers (Beatle Bass, Jaguar), Jazz with both pickups, PJ’s with only P and PBass seems immune to perfect orientation.

I’ve also abandoned the ZNR noise reduction in my Zoom B1X Four. I prefer my tone without noise reduction trickery…

 

[beans-on-toast]

How do I know if the xformer on the pole has something to do with induced noise in my pickups/basses? Any way or app to monitor?

It’s a possibility, one of many. They can test for noise radiation with equipment. If you explain that you have been dealing with this issue and had your electrical entrance changed in an attempt to resolve the noise, hopefully they will investigate it.

As you saw in the video, external noise influences can be a pain to resolve.