Testing Potentiometers for Log or Linear

[thedwest]

I built the VHS recently and while I like the sounds I'm able to get out of it, it feels like most of the adjustments on the pots is either in the first quarter turn or the last quarter which made me think that i might have put A100K pots in instead of B100K. On the volume pot, i don't notice any difference until well past half way and on the chorus pot, its seems like most of the adjustment is in the first quarter turn. I'm trying to find the best way of determining if I made that mistake. This feels like a dumb question because I have a simple solution for this, which would be to just desolder the DC jack and remove everything from the enclosure but it seems like anytime I have to do that, something gets messed up in that process so I'm trying to avoid it. Not sure you can test for log vs linear but thought I would ask. I'm also going to go through and reflow all of the joints I can access to see if that helps. Thanks!

 

[Robert]

Turn the pots to Noon and measure the DC voltage on Lug 2 to ground. (with power applied to the pedal, obviously)

If it's a Linear pot it should measure around 1.65VDC. If you measure significantly lower voltage then it's probably a Log pot.

 

[thedwest]

Turn the pots to Noon and measure the DC voltage on Lug 2 to ground. (with power applied to the pedal, obviously)

If it's a Linear pot it should measure around 1.65VDC. If you measure significantly lower voltage then it's probably a Log pot.

Great, thanks! i will give that a try.