Ibanez CS 505 (issue with Depth control)

[baikonour]

Hi Guys,

I have acquired a CS505 lately, really nice sound overall, but I have an issue with the DEPTH control...It jumps from very little (or none) to what I think is full on (from 9 o'clock.)
I have swaped the potentiometer with another one, but this didn't make any difference. So the issue seems to lie somewhere else...Any idea?

Thanks a lot

[52 Bill]

Welcome to the place.

...I have swaped the potentiometer with another one, but this didn't make any difference. So the issue seems to lie somewhere else...Any idea?

When you swapped the pot, did you change the pot taper?

[baikonour]

Hi 52 Bill,

I have used a pot from another pedal, same value, I have since resoldered the original pot.

I have found a picture of the circuit board, I don't know if this can help,but I guess I can post it here.
There are 2 adjustment screws on the circuit board but these are for the BBD bias.

[52 Bill]

I have used a pot from another pedal, same value, I have since resoldered the original pot.

A normal pot is a variable resistor. The basic resistance is connected to the two outer terminals and the third center terminal is the wiper, which slides across the resistance path. Pots have a specification called taper. This relates to how the resistance value at the wiper changes as it slides from one end to the other. If you go to RG's site he has a detailed explanation of how all of this works.

The basic idea is this, if the pot that you have in the pedal reacts too fast because the resistance changes too fast, then change the pot to one that has a different taper where the resistance will change at a slower rate and the sound change will slow down as well.

[baikonour]

Thanks 52 Bill, Which taper value would you recommend? Also just as an info point, if the pot is original (it does look it but who knows for sure) why would I need to change for another one with a different taper?

[52 Bill]

Which taper value would you recommend?

What taper does the original pot have? Are there any markings on the pot?

...why would I need to change for another one with a different taper?

Because you don't like the way the original one works. The person that specified the original pot chose the one that's in there for some reason. It could be he liked the way the control reacted or he didn't pay attention to it and didn't think that anyone would care about it.

There are entire companies out there that got started by doing mods on manufactured pedals. They changed resistors and capacitors to make the pedals sound or work better than the original designs.