Doepfer

I'm having a few problems with pitch.
If I take a voltage out of the 155 - through a splitter to a 111 & two 110's. I can't get the three in tune with each other. The two 110's are similar, but the 111 is about a fifth out, and the tune knob hasn't a big enough range to fix this.
I thought maybe the splitter was the problem as the pitch was different after the splitter, so I got a bus access to send the 155 voltage into the bus to the oscillators - this didn't help and seemed to go more out of tune.

Any ideas. Is there some internal adjustment on the oscillators which needs adjusting?
Also if I take a voltage and want to split it to control the pitch of a few oscillators then what is the best way? I also picked up a buffered splitter off Analogue Solutions which I thought might be more stable with voltage.

peace James