Expression pedal jack

[Freppo]

Hi folks

I want to add an expression pedal jack to one of my project, and I need some advice.
Looking at expression pedals, there's a wide range of different values avaliable which is a bit confusing.

What pot value should I use in my project for the best general expression pedal compability? 10K?
It will control the speed of an LFO, so it's possible to modify the LFO for almost any pot value.

Cheers
/ Fredrik

[midwayfair]

Use a voltage divider method for whatever you want to use the expression pedal for and the value won't matter.

[Freppo]

Thanks

I'm don't think it's possible through in this specific project, since it will replace a variable resistor in a schmitt trigger (CD40106) oscillator/lfo.

[midwayfair]

Put a cap on a dip switch to change the cap to go between one appropriate for 25k versus 10k. That will be preferable to using a parallel resistor I think. The problem is that 10k expression pedals are b taper while 25k is likely to be an EB Jr which I think is A taper. If you're making a one-of, it's probably better to just ask them what they're going to use and design the build around that. If you're making lots, then it's worth it to redesign the project to ensure that it works with whatever the customer plugs in. I had a thread in DIYSB last year asking for voltage divider rate controls if you want to see what's closest to what you're already using.

[Freppo]

Thanks for the tips Jon.

The cap/dip-switch idea is excellent. I will be making many of these, but I not sure if I will add the expression jack.
It was more of an afterthrought, and the main PCB is already ready.. but maybe for the next project