How to stop waterboarding

Hey powder,

You can get a power condition with a "voltage regulator" however, those fixes are kind of coarse and probably not related to the issue you are having.

Here's an example:

https://amzn.to/3cHrepu

However, without understanding your system better I don't think this is a solution for you. 

Is this happening with all inputs? Vinyl or digital?

What exactly does this sound like?  Like a motorboat?

I've never heard the term, with regards to stereo gear. Waterboarding? I'd like to understand. Gosh hope it's nothing you've personally gone through..

Noise is usually routing, or ground loop issues, but you're a little light on details.  Do you hear it through all the drivers or just the bass section you reference? Like E said, what's on, when it happens?

Regards

I’ve been waterboarded on this forum a bunch of times.  

Do you mean motor-boating?

I suspect OP means "motorboating" which admittedly is a form of torture to the ears.  I experienced this once and it was due to my router being in close proximity to toroidal transformers.  Problem instantly solved when I moved the router about 8 feet from the rack.