can i just apply 0 - 5v dc signals… do i have any thing to worry about…
i was looking to come of a HC11 micro and go through a d-a and an op amp..
i have all my levels in the 2 volt octave
precautions?
Litterature is quite clear. For LP, it goes like this :
Pitch and Filter CV : -5 to +5 V
Volume CV : 0 to 5V (that the output of the Moog Expression pedal)
Keyboard gate : +5 trigger
CP-251 has a bit more tolerance on some input. Attenuator is -8 to +8. Check the book to make sure if you have one.
Experimentation in encouraged, still it suppose the handler has basic notions about voltage and DC stuff.
My Les Paul guitar has too low output to be used as is. Only mild modulation was detected. I have been experimenting with a factor 10 gain preamp circuit based on an easy to find opamp (741), powered on 12 volts BUT with a 5v Zener diode to limit voltage. So far so good, I have guitar driven LP 
Guitar controls the parameter of its CV input, it’s not a guitar synthesizer just yet.
That will happen when the guitar is plugged in as audio source. At that point, i’ll be using a J-fet based circuit for better sound (op amps are noisy). I am still at the early stage of experimentation, but I am sure there’s a lot of fun yet to come.
You’re doing the right thing by asking. Your equipment’s warranty covers manufacturing defects, not foolishness. 