Ok, that changes things a bit.
Distortion can be a result of wrong bias somewhere. Probably at the input of the BBD.
My suggestion would be analysing parts of the circuit:
First, remove the mix resistors (If the MN3207 is socketed removing it will break the signal chain there, and no desoldering is necessary).
Let's hear how it sounds without chorus at all (just the clean sound). If there is something wrong with an OpAmp it should be noticiable.
Second, there should be no distortion (when using the audio probe) until you get to the input of the BBD. Chorus do not have feedback, so there should be nothing returning to the begining of the signal chain.
Third would be to remove everything associated with the BBD (clock, BBD, LFO(TL062)) and see if the clean signal works now.
That should give an idea where the Problem is.
Distortion can be a result of wrong bias somewhere. Probably at the input of the BBD.
My suggestion would be analysing parts of the circuit:
First, remove the mix resistors (If the MN3207 is socketed removing it will break the signal chain there, and no desoldering is necessary).
Let's hear how it sounds without chorus at all (just the clean sound). If there is something wrong with an OpAmp it should be noticiable.
Second, there should be no distortion (when using the audio probe) until you get to the input of the BBD. Chorus do not have feedback, so there should be nothing returning to the begining of the signal chain.
Third would be to remove everything associated with the BBD (clock, BBD, LFO(TL062)) and see if the clean signal works now.
That should give an idea where the Problem is.