Hi, guys. I have quite recently completed my 4x Midibox SID, but now I have started to notice all the noise it generates. It is only noticeable when not playing and it sound really "pointy" like a sawtooth wave. The noise can be reduced almost completly by setting the filter, and on some patches, for example "NT Bass" there is almost no noise at all. What I'm wondering is if the noise comes, internally, from the 6581:s or if something else might contribute to the problem? I have tried with different PSUs, without any luck. My filter capacitors are all 470p and all my chips sounds pretty much the same. I hope I have described the problem well enough and I really appreciate all the help I can get! Best Regards, Jack from Sweden.