Why is this please???? Was: RE: [sdiy] MFB SEQ-02 question

[David Ingebretsen]

Alright. I've pinned down exactly what causes the ripple in the SEQ-02.

In essence, if I use a patch cord made from shielded cable longer than about
10 cm, regardless whether or not I connect the shield at either end, it
creates this ripple when I plug it into the CV output. On the bench, in the
rack, regardless. It always does.

If I use a single conductor wire, regardless the length within reason, to
patch the SEQ-02 anywhere else, all is good, with one exception. If I plug
the SEQ-02 into a multiple and plug a shielded cable into the multiple, I
get the 2 volt peak-to-peak 400 kHz ripple again.

So, what magic is the shield doing to introduce this ripple regardless
whether or not it is connected to ground?

The easy fix is to make up a bunch of single conductor patch cables, but I'd
love to understand why.

Thanks
David