Annoying high pitch noise introduced through power supply?

[Mihkel]

So, if i have all my true bypass pedals bypassed and the power supply switched OFF, i get a good sound from my amp, nice and silent. But as soon as i switch the power supply on, with the pedals still bypassed, i get a constant beeping noise, it's still there when i switch the delay or the wah on, but goes away when im using the phaser or distortion. Im using the regulated PS from GGG (not the ultra clean one), the daisy chain cable i made doesn't have the highest quality 2,1mm plugs and some of them are a tad loose. Could a bad power cable cause this noise?

Thanks