Buzz noise when plugged in power outlet - but fine when on battery

I've noticed when I plug my S1 Pro into an outlet, I get a lot of buzz/hissing sound when it's turned to the halfway point (even a bit under). I've tried a few power outlets along with a power bar and have the same issue. 

Is there a trick to minimize this? When it operates on battery, there is no hiss. I've also tried a power different cable so I don't think that's the issue.

I realize it could have something to do with what instrument is plugged into it however, again, that noise doesn't exist when it's on battery. 

Thanks for any suggestions!

Levko, have you plugged into different plugs in different buildings or all in the same building? In my experience some buildings have worse hum than others (maybe an issue with the grounding in their electrical system?). Not sure, but some bars I play at there is hum and others none at all!


I invested in a really good surge protector with three independent grounds and it worked wonders. 

I've just tried it in the same building. I got a higher end surge protector but it doesn't make any difference with the hissing. I just wasn't sure if there was a trick to an issue like this as I only use this in the same building for the most part. Thanks for your help!

Wish I could give you a better answer. Hopefully someone else here will have some further insight. 


Good luck

Check the cable that connects the instrument to the S1.

When plugged in, the A/C current flowing into the unit causes fields that aren't present when running on battery and can be picked up by a defective guitar chord or mic cable.

I've tried a variety of cables that I own (Planet Waves, Fender, etc) - I've tried all of them and still get that hiss. Thanks though! 

So many moving parts...  🙂

I've (rarely) heard a little hiss and hum from my S1s when plugged in but found that it was being generated by my QSC Touchmix (sometimes) because it went away when I muted the output from my mixer.

Again, the major culprit is often a ground loop or some such which is why I try to plug EVERYTHING in the system to ONE grounded plug and use extension cables and power strips to distribute that ONE A/C source to every device.

I would try it on a generator or a different building.

Many power conditioners on the market incorporate Electro Magnetic Interference and Radio Frequency Interference (EMI & RFI) filtering and wiring fault detection to help fix those noise issues.

Thanks for all the responses  - I would try a different building but it's my house unfortunately. I will look into the power conditioner avenue, much appreciated!

I run into this often with other buildings and have yet to resolve it.  Shy of coughing up a good chunk of cash for a power conditioner.  If you could find a generator to try it on, that would at least confirm, before you spend additional money.

These problems don't seem to go away easily......

Hi Levko,

I'm sorry you're having an issue with hiss and buzzing when you have the S1 Pro connected to AC Power.

For diagnostics: With NOTHING CONNECTED to the S1 Pro - Please tell us what you hear.

  1. Battery Power Only
    • Turn up all the volume controls to 12:00
  2. AC Power (No power conditioner or power bar)
    • Turn up all the volume controls to 12:00
  3. AC Power (No power conditioner or power bar) in a different location (different building)
    • Turn up all the volume controls to 12:00

Do the same tests with a microphone connected to Channel 1 (others turned off)

Do the same tests with a device that you're using now on Channel 1  (others turned off)

If you hear a loud hiss/buzz with AC in several different locations, you may have an issue with your S1 Pro system and you want to call Bose Support.

Bose® Product & Technical Support at (877) 335-2673
(U.S. and Canada only)
Monday-Friday: 9:00 AM - 9:00 PM ET

Another approach: It looks like you are in Canada. If you are close to a Long & McQuade store, check with them to see if they have an S1 Pro system in stock. They will probably let you come in and compare yours to a unit they have on the floor.


Thanks everyone - I did connect to a generator, there was some hiss but better than plugging into my wall (about half the amount of hiss). 

Regarding the tests:

On battery with nothing in it (1) - I get some noise at about 80% but I don't think that would be unusual - that's just on the two channels - there is no noise when I turn up the bluetooth (nothing connected to that). 

Straight in wall (2/3) - hiss is worse than battery, starting about 70% way mark

With anything plugged in, the hiss starts at about 40%.


I guess there's dirty power in the house that's causing some interference and it worsens with use of an instrument cable/xlr. It doesn't seem to make a difference if I use a surge protector or not (I've tried a variety of cables and surge protectors and it's about the same hiss with each one). 

Not sure if there's any general hacks to fix this issue in a house. 

Hi Levko,

sorry to hear about your sound problems when using mains power.

With this sort of problem (unless it's some fault in the unit itself, and ST's made a few suggestions along this line e.g. comparing it to another S1), I would be wanting to try out a good power conditioner (not just surge protection, but really something that cleans up any interference present in the mains supply). These things can sometimes work wonders. Many professional sound engineers won't work without them and use them whether the power supply is noiseless or not..

I hope this has helped in some way. 

Please keep us informed of any progress you might make with regard to this problem.


In case anyone is in same scenario as me regarding noise when plugged into  a wall socket, I did buy a power conditioner as suggested (Furman SS-6B) and saw zero improvements. I even tried plugging in the Yamaha PSRS950 into the same Furman power conditioner bar as the Bose S1 Pro but no difference.

I guess I'll just be charging it and using battery power to avoid the noise. 

If anyone has had a similar problem and found a solution, I'd be grateful for the info on how they fixed it.



Hi Levko,

I'm sorry you're still having this problem with noise when you connect your S1 Pro system to AC Power.

Did you try taking the S1 Pro system back to Long & McQuade?

Another approach: It looks like you are in Canada. If you are close to a Long & McQuade store, check with them to see if they have an S1 Pro system in stock. They will probably let you come in and compare yours to a unit they have on the floor.

And you can call Bose Support. I know they'll want to help.

Bose® Product & Technical Support at (877) 335-2673
(U.S. and Canada only)
Monday-Friday: 9:00 AM - 9:00 PM ET


Bose actually swapped it and I'm having the same issue with the replacement so that's why I thought others may have a solution. Thanks

Have you tried to plug it in at a different building/venue?  Betcha it won't happen there.

Hello, Alex.

Please see this new discussion for your question.

Buzzing from S1 pro connected with the L / L R output of my Tyros 5 keyboard.

Thank you, 

Bose Pro Community Admin 

I wish I wasn't happy you were getting a buzz sound too but it does make me feel a bit better that someone knows what I mean, I hope you find a solution and hopefully you can let me know.