Need help with pots oriantation (always confuse me!!)

[arma61]

Hi m8s

so I'm trying to make a PCB layout for the Vulcan Preamp, I want to make it with "pots on board" so to be fixed on an aluminium panel. But everytime it comes to pots orientation I end with cutting traces on PCB and add jumpers as the pots "turn" the other way round (you know what I mean   )

so I need you help!, looking at the schematic      (better quality link)    




and to this (partial) layout (you're looking at the board from top, oh but you know that !  )



are the pots connected in the right way?, I mean, taking that the board is mounted on a panel so looking at it with Level on the right and Gain on the left, will Gain, Level etc.. increase ( so more Highs, more bass etc) turning the ports to the right, so CW ?

My breadboard is so small (25 rows!)   , I need to buy a bigger one, very usefull in this case!

thanks for help m8s
Armando

[GibsonGM]

Look at the gain pot....provided the black trace is ground, it is wired correctly if you are looking down at the PCB, top being the front (as you said).

A pot wired this way will short the signal to ground when turned CCW, and before that the resistance from input to wiper will increase (lowering the signal).   So, your grounds should be on the left.  Go back thru and verify that they're all operating this way (it's early here, no time before work!). 
It helps to picture a pot as a slider as on a mixing board....more 'space' above it = a higher resistance in the divider and therefore lower signal output....
Good luck!

~MJP

[walker]

I found this helpful  http://gaussmarkov.net/wordpress/parts/resistors/resistors-5-potentiometers/

thinking of the lugs in terms of clockwise (CW) and counter-clockwise (CCW) was an eye opener for me. 

[arma61]

thx ms for help!

I think I got now about Level and Gain pots and I should be able to work out the other pots connections.

walker, thanks for that link, funny enough I was just browsing that site (dr boogie has almost the same tone stack) looking for suggestions/confirmations!

time to etching!!

Armando

[Brymus]

I always get conufesed too,and I never remeber which is lug 1 and which is 3 
So I try it on my breadboard every single freakin time, then leave an example of the circuit on my breadboard when I wire the actual pedal this has saved me a ton of frustration ,in making simple mistakes,yet I still managed to wire the controls on my drummers FF backwards

But I have read there is a proper way for drawing pots that rotate CW vs CCW and IDK that everyone draws them right on their schematics.
It would be nice to know the correct way for drawing pots when they are supposed to work one way vs the other but that changes with the design as well.

For instance I have a pedal that actually increases the clipping when turned CCW if wired the normal way so therefore to have it increase clipping when turned CW it has to be wired backwards

[walker]

no problem Armando.  My first attempt at wiring up a pot involved a voltage sag, and I ended up igniting a pot due to errant wiring.  Sparks, smoke, stench, and all.   The gaussmarkov site was super helpful.  I really like the colored 1/4" jack diagrams too. 

[Ronsonic]

Easiest way to learn it and always remember it is to take a pot apart and look at just how it works and visualize what it's doing. You'll see the wiper get closer to one or the other outside leg as you turn it with less resistive material in the path the resistance goes down. The lug that it approaches when you turn it clockwise is your "hot" lug.

[petemoore]

  Shaft facing, legs down in back...turn CCW Minimum volume, imagine the knob pointer points to the left lug.
  That's for volume...
  But what works for any surrounding circuit is to think of the pot as 2 adjustable resistors that when added always = that pot value.
  Or a resistive strip, wiper in the middle is 50/50 resistances, a little toward from center CW is 40/60, a bit CCW of center is 62/38.
  For ease of discussion I chose a linear pot, audio pots are like a curved hill on a graphic [goes up sharply on the one side, down sharply on the other as the pot is turned from all the way < to all the way >]. Linear pots...draw a diagonal line on the graph/chart, they're ...flat.
  I think of audio pots like the wedge with the curved up right side, linear like the standard-straight wedge seen above or below the volume controls on our screens.
 

[GibsonGM]

The beauty of point-to-point wiring rather than lugs-in-the-hole PCB connections is that if you wire it backwards, you can move 2 wires and having it working right  ;o)