Modular Synth Panels

I remember bugs saying that the LF442 couldn't be swapped, at least not 
in his pcb layout for the XR VCO.
Mine already has the TL074 in there by the way.

> Just had another coffee and swapped the chips and as Mr.Stites 
> predicted all is well with the TL074 but I'm still putting the LF444 
> back in :)
>