new scans: some JH-720 schemos

[jhaible]

> Besides that i was once again looking at the Polysix
> shemos and was thinking again about that one should
> do some muxed current mirror stuff, one can mux
> the linear part for linear FM in the same clock
> cykle as the cv. Well depending on the OSC used
> one can do the FM on the other side of the
> mux.

Make sure your MUX is clocked fast enough. The sampling rate must be
twice as high as your highest relevant harmonic in the signal you're
using for FM.

JH.