I have some pedals the last few days and i use pots named Alpha... i have built two identical pedals and one of them have some problems with the Treble pot, it works the wrong way even though its a A10k like it should be.. maximum is no Treble and zero is maximum Treble.. i cant figure out why... anyone have a clue ?
If pots work the opposite way, simply switch the wires going to the two outside lugs. (put the left right, and the right left)
IF you think it's the wrong way , it's 1) your accidental doing 2) Design . Design .
The thing in that both those pedals are exactly the same, wired the same way and i have double checked it all several times to get an understanding why the Treble pot on one of them are different....
Which pedal is it you built?
The pedal i built is similar to Guvnor but with some changes to it, so, but does not really matter cus they are both exactly the same... but still dont work the same.. :S
Quote from: Perkla on February 12, 2012, 11:09:10 AM
The pedal i built is similar to Guvnor but with some changes to it, so, but does not really matter cus they are both exactly the same... but still dont work the same.. :S
You might have got a accidental mislabelling of a Rev.log pot , those don't come cheap .
There's two alpha pots , 1 from taiwan and 1 from USA .
Quote from: DavenPaget on February 12, 2012, 11:14:09 AM
You might have got a accidental mislabelling of a Rev.log pot , those don't come cheap .
That only affects the taper though, it doesn't make the pot work backwards. For any taper, if you measure between the anti clockwise lug and the wiper, resistance increases as you turn clockwise. If you measure from the clockwise lug to wiper, resistance increases as you turn anti clockwise. I can't see any way that a manufacturing error can somehow reverse this.
The only way I know of to make a pot work the opposite way to what you expect is to wire it up the wrong way round.
Quote from: slacker on February 12, 2012, 11:49:30 AM
Quote from: DavenPaget on February 12, 2012, 11:14:09 AM
You might have got a accidental mislabelling of a Rev.log pot , those don't come cheap .
That only affects the taper though, it doesn't make the pot work backwards. For any taper, if you measure between the anti clockwise lug and the wiper, resistance increases as you turn clockwise. If you measure from the clockwise lug to wiper, resistance increases as you turn anti clockwise. I can't see any way that a manufacturing error can somehow reverse this.
The only way I know of to make a pot work the opposite way to what you expect is to wire it up the wrong way round.
The taper for him is exactly reverse of a log pot .
Like I already said, changing the taper doesn't make the pot work backwards. Using a reverse log pot, maximum and minimum treble would still be in the same positions on the pot as for a log or linear. It's only what happens between minimum and maximum that changes.
Look at this graph from R.G's Secret life of pots, that shows what I'm on about.
http://www.geofex.com/article_folders/potsecrets/pottaper.gif (http://www.geofex.com/article_folders/potsecrets/pottaper.gif)
http://www.geofex.com/article_folders/potsecrets/potscret.htm (http://www.geofex.com/article_folders/potsecrets/potscret.htm)
Quote from: slacker on February 12, 2012, 12:28:36 PM
Like I already said, changing the taper doesn't make the pot work backwards. Using a reverse log pot, maximum and minimum treble would still be in the same positions on the pot as for a log or linear. It's only what happens between minimum and maximum that changes.
Look at this graph from R.G's Secret life of pots, that shows what I'm on about.
http://www.geofex.com/article_folders/potsecrets/pottaper.gif (http://www.geofex.com/article_folders/potsecrets/pottaper.gif)
http://www.geofex.com/article_folders/potsecrets/potscret.htm (http://www.geofex.com/article_folders/potsecrets/potscret.htm)
Oh ! Right . Sorry for my utter ignorance .
I think he really swapped the wiring . Am i right to think that a rev.log pot is a log pot wafer in reverse ?
Take the pot out of the circuit and measure it and then you will know for sure.
Andrew.