Static Noise with Headphone

[Strellson]

I just bought a used prophet 08. The seller bought it new in March.
When i play with Headphones on, i noticed static noise on the left headphone speaker on release of the sound - when the sound fade out. after a couple of minutes the static noise becomes permanent. when i touch the headphone jack it gets quiter for the moment i touch the jack. i change the adapter, but the nose is still there!
i try to record it through the headphone jack into a audiointerface. but - the noise dissapears. plug the headphone in again… noise comes back!
the headphones (audio technica) works perfect on every other source.
the static noise always have the same level. doesnt get louder when i turn up the volume. i guess headphones with higher impendance will solve this problem but …
any idea what the reason for this is?
thanks!

[jdt9517]

Is the noise present when you use the line out jacks?  If so, then it may be a part of the sound, or a problem with the output circuitry.  If not, it is either a dirty headphone out connector, or a bad bit of circuitry in the headphone out preamp.

[Strellson]

No, only via Headphone. Connected to my DAW is fine!
DSI allready send me a new PCB Audio Out Board. Hope this will fix it.

[Strellson]

I received the exchange audio out board. Replace it. And now … i have high distortion on every preset i play …
Only when i using headphones.
when i use main outs into my desk everything is ok.
even when i plug phone out into my desk verything is nice!
but every headphone i plug direct to the prophet generate distortion. worse then before the exchange of the board.
 

[MartinM]

Moinmoin,

what is the impedance of Your headhone(s)?
Maybe You should try other headphone impedances than Your actual ones (use 32Ohms if You used high impedance ones so far or vice versa)
What is the result?

Martin

[Strellson]

Hi Martin!
I try today 250ohm headphones and everything seems to be ok.

[MartinM]

Moinmoin Strellson,

good to hear, that everything is fine.

Martin