Noisy power supply?

I have an MPC live (gen 1). Been working flawlessly and still does, but I noticed on the last session a really present electrical hum. Didn't feel like dealing with it, so I waited until tonight's session. It sounds even worse.

The thing is, as soon as it's on battery and the PS is unplugged, it's nice and quiet! I'm thinking this should be pretty straightforward, just a PS that's original and is dying on me. Should I just get another PS? I've tried it in all of my usual power sources (power conditioners, various strips, wall outlets), and it sounds the same.

I'm just going to use it to charge the MPC and when I use it, I'll run it on batteries.

Thanks.

Is this happening when the MPC is on the power supply and you only have headphones connected (nothing else)?
Or does it manifest when you plug the main outputs in?

On the plus side, it doesn't get rendered into your tracks or samples.

Neurone wrote:Is this happening when the MPC is on the power supply and you only have headphones connected (nothing else)?
Or does it manifest when you plug the main outputs in?

Either.

Ultros wrote:On the plus side, it doesn't get rendered into your tracks or samples.

It's definitely coming out of the outputs, so I don't know if it would happen on a render.

I mostly use this as a brain for all of my synths, so I'm not really rendering anything.

Is it the Correct Power Supply?

40Beatz wrote:Is it the Correct Power Supply?

Yes, the one that came with it.

New power supply then

Neurone wrote:New power supply then

That's what I figured.

Try a ground lift plug, I find that to be essential.

USB connections can exacerbate this.

jamos wrote:Try a ground lift plug, I find that to be essential.

USB connections can exacerbate this.

He tried with only headphones connected. No USB, no other connectors, just headphones.
Ground lift or isolation transformers won't help if the ripple/RF is internal.

If a proven DC clear power supply does NOT resolve it in isolation only then should he start to investigate the unit itself.
I'm presuming the MPC has some basic power conditioning or polarity protection, if the hum can be heard with just headphones and with a new supply, then it's time to investigate internally.

Neurone wrote:

jamos wrote:Try a ground lift plug, I find that to be essential.

USB connections can exacerbate this.

He tried with only headphones connected. No USB, no other connectors, just headphones.
Ground lift or isolation transformers won't help if the ripple/RF is internal.

If a proven DC clear power supply does NOT resolve it in isolation only then should he start to investigate the unit itself.
I'm presuming the MPC has some basic power conditioning or polarity protection, if the hum can be heard with just headphones and with a new supply, then it's time to investigate internally.

The power supply is inexpensive, so it's worth it. If it doesn't do the trick, I will then dig deeper.

does it hum when the pad lights are off? (just curious) another user recently made a point about how the mpcs arent well sheilded and the light emitting diodes are pitching rf interference the machine then inducts and becomes present in sound. I wonder if some copper tape would fix a lot of our problems. you are not the only one. i have this issue too on my mpc one and its been there since day one. I bought a power conditioner, use strictly din with synths and gear on same conditioner nada... tried a diff power supply nada.. lol i am tempted to go in and start soldering wires from everything to a ground point.. none of us have found the answer yet. We need a user who owns a scope to isolate the origin of the noise. for example, sample something in and look at the wav. notice theres no noise in that?