Tonepad Chorus question

[ethrbunny]

I built this http://tonepad.com/project.asp?id=53 from tonepad recently. Worked great until I tried some of the mods (d'oh!).    I restored it to its 'unmodded' condition but its still dead. Bleah.

In any event - what does the trimmer pot do?

[bluesdevil]

The trimmer pot seems to go from dry  signal with no effect to chorus effect with distortion from what I remember. You want to set it for loudest effected signal with as little distortion as possible.
    Some of the mods don't work very well according to the user comments on the site, but a few work great. Range and intensity mods, plus the vibrato switch worked great on my build. I used a rotary switch to chose different caps for the delay range mod..... goes from flange to a very weird time delayed chorus and everything in between. 
      Hope you get it working again and good luck!!!!
       

[ethrbunny]

Im v bummed that it stopped working. I was trying to find a way to increase the depth and use it as a vibrato unit. My kingdom for a variable capacitor!

Im a tad worried that I bollixed the delay chips with my cap changes.

Time for an audio probe I guess.

[Mark Hammer]

The trimpot sets the bias for the delay chip.  The chip needs to have the audio signal sitting on top of a DC voltage.  Think of it like a child who has top put on platform heels to get into a club for grownups.  If the heels are too short they're kept out of the club.  If the heels are too high, they hit their head trying to get through the door.  The trimpot helps adjust the height of the heels properly.

[ethrbunny]

Wow Mark - great analogy!

Now explain why the chorusing part has quit working. Im still getting the clean signal though. Waaah!