VCO trimming + VCO as an LFO?

[kupfer_m]

Hi,

When trimming my Yusynth VCO (BC547 version) I could not get a correct
V/OCT trim. Trimmer T2 reached the end of its range before getting the correct V/OCT step. I found that lowering the 33k resistor in series with T2 to 22k did the job for me. The VCO now tracks correct!
Just want to share my findings.

Another question: when trying to trim I noticed that the VCO could produce very low frequencies. What adjustment could be made to turn the VCO into a VC-LFO?

Thanks,
Jim

[yusynth]

Are you using BC547B as indicated ? Were R3,R4,R5 and R11 1% tolerance ?

You can turn it to a LFO by changing the value of C8 (making it 2.2n but the V/Oct tracking might not be as good)

[kupfer_m]