Brand New Rackbrute 6u with the same high pitched noise others complained about

[bombshelboy]

When I switch the Rackbrute on (no modules wired) a high pitched buzzing/swishing/ringing can be heard until I switch the Rackbrute 6u off. My Minibrute 2s does not do the same noise.

[bombshelboy]

false alarm! Apparently my Peavey effects rack was bleeding AC noise...resolved by removing it entirely (I was considering it anyway)

[n-gram-music]

Can confirm. Same issue, just at edge of hearing, oscillating. North American power, and power supply / plugs. However, unplugged from full power bar and plugged directly into wall socket, problem goes away.

Plug power back into full power bar - problem isn't there anymore.

This implies there is some kind of heating issue where when you leave it on long enough drawing power from modules, you get that feedback. Now that it is plugged back into the power bar, I am going to see if it appears again over time.

If it does, I will leave it plugged into the wall directly again, but for a longer period (8+ hrs) to see whether the problem appears again as a result of the rackbute drawing power over time, or if it's the power bar drawing that extra much power over time.

The noise has only appeared when I got a new moldule (QuBit Bloom) and left the RackBrute 6u on for the afternoon while I was playing with it.

I suspect it is the power bar being pushed to its limit. If you do not see a follow up from me, it's because I isolated the noise to being caused by the power bar, or I died of myocarditis from the shot.
 

[n-gram-music]

Waited a few hours, plugged into power bar, noise started up again. Trying wall power in the morning. Willing to bet it's related to this: https://www.howtogeek.com/200466/WHY-DO-SOME-AC-ADAPTERS-AND-POWER-SUPPLIES-MAKE-A-WHINING-NOISE/

implies power cable replacement instead of board in unit. As a heads up, can you guys test some cables and make them available for sale? I'm not going to haggle over warranty receipts, I just want to to make my stuff work.

[n-gram-music]

Following this up, the ringing noise issue did not appear when RackBrute 6U plugged into the wall for multiple hours, which implies it is the power bar, and not the unit or the cable/transformer in this specific situation.

Recommendation to others if you have this issue: try changing the power source before looking at replacing either the cable/power supply, or anything in the unit. If you have a separate circuit in your house, try it on that as well. If it's the same everywhere, then explore option of replacing cable, imo.