I have finished my Duo Phase but the rate seems too fast.

[Saransk93]

Both the A side and B side have this issue. The rate control only is usable in the first third of the rotation and then it gets too warbley. Whatever mistake I apparently did it on both sides.
A quick visual check doesn’t have an “ah hah” moment.
Any idea what is wrong
Thanks
Michael

 

[owlexifry]

Both the A side and B side have this issue. The rate control only is usable in the first third of the rotation and then it gets too warbley. Whatever mistake I apparently did it on both sides.
A quick visual check doesn’t have an “ah hah” moment.
Any idea what is wrong
Thanks
Michael

 

[Saransk93]

Ask and you shall receive
Michael

 

[owlexifry]

the vast differences in these trimpot settings (from left side to right side) leads me to believe that they may not have been dialled in 'correctly'

 

[Saransk93]

I noticed that but from what I can tell, neither trimpot actually has any direct effect on the rate of the LFO.

 

[Betty Wont]

I noticed that but from what I can tell, neither trimpot actually has any direct effect on the rate of the LFO.

They do not. Perhaps you used the wrong taper for the rate pots? Perhaps the rate is subjective and it is behaving normally. Have you compared yours to demos of this circuit?

 

[Saransk93]

I thought that as well but I checked and both said B25K
I looked at the original Mu-Tron Phasor II schematic and the LFO is exactly the same as used in Duo-Phase except for one important element, the Rate pot in the original is a 25KA (audio) as opposed to a 25KB (linear)
Could this be a typo in the Duo-Phase build instructions
I’m going to swap out the B25K with an A25K and see if that makes the control more responsive. Hopefully that will work and it won’t need C25K (reverse A)