Doepfer

Hi folks, I have an A-196 PLL, and I have a simple question. The 
internal VCO seems to behave much better given the LPF input than an 
external VCO. The LPF signal is typically way too jittery for an 
external VCO. The only way I've been able to get an external VCO to 
work is to patch the COMP output to a slew then to the external VCO. 
Is there something wihtin the circuit between in the LPF output and 
the VCO input? Or is the internal VCO special or slewy compared to 
typical VCOs?

Thanks,
Doug