Tone (hum) in MBP via audio out port

[Drumstruck]

I remember reading about this somewhere sometime someway ..... when using an MBP audio out port there's a hum or tone (approx 300Hz)


was I dreaming? that hum is a pita

[gigpiglet]

lots of laptops have power issues with their audio out
but no - you shouldnt be hearing that..

ive plugged plenty of laptops in to large PAs for background music, sponsor reels, sting music etc
and if there was anything like that i would have heard it.

though you do sometimes need to be careful about where things are getting power from as always

[Drumstruck]

thanks Gareth - I remember now someone else thought it was related to p/s on the MBPs.

There is no tone going over f/w - just through the h/phones socket.....

[gigpiglet]

yep power supplies on laptops in general suck

but thats what i meant by my post above, I've used the phones socket a million times at shows, to playback into the PA and never noticed an (on going) problem

sometimes ive had earth issues that needed an isolator to lift or whatever
but no "every mcbook has a 300hz hum" issue

maybe someone had a specific issue in one place with one power set up, and decided it must be all macbooks?