Florian discribes, how to re-route the Crossmod zu the Filter to get nice Filter FM instead, or just make it switchable.
OMG, I must do this mod!! But switchable. Here’s his words quoted:
Modification No.1: Change VCO2-to-VC01-modulation to VCO2-to-VCF-modulation
While VCO-to-VCO-modulation cannot be played tonally, the VCO to VCF modulation can be played tonally and is an increadible enhancement for analogue subtractive synthesizers tonal possibilities. Usually it is dead simple to achieve – also at the JP6:
This is a modification I did not yet try, but it looks idiot proof to me. If any tries this, please let me know about your results.
*) later models have different partnumbering: R41 to IC49
@ Forum: Roland Jupiter 6 – Crossmodulation -> FilterFM zu finden im DIY Subforum..
and there’s also a nice image-gallery about restauration of the Jupiter 6 as well.