I've got a Jupiter 6 with the Europa mod in the shop and if an external clock source is used for the arpeggio, the internal clock and external clocks are summed. This is an easy problem to solve, by just turning the internal clock's rate to zero before switching to external clock mode... however, I"m curious if this is the way it is supposed to work, or if it is a malfunction.
if I boot the synth to the stock roland code, the internal clock shuts off when an external clock source is plugged in.
if anyone has a jupiter with the Europa mod and could check this, I would really appreciate it!
Do you have Ext Clock sync selected with ARP Down + Bank B? External clock is not 100% stable and is one reason the 2.0 beta still hasn't been finished. Jeffrey at synthcom said he hoped to get back to it sometime this year...