Touch sensitive volume control

[Chris Riddell]

Hi Guys,

I've been wanting to add a touch sensitive volume strip to a guitar project but running into some troubles, Here's the standard wiring diagram that's currently used:

http://2.bp.blogspot.com/-9cBXOSncB...VO0/s1600/HSS-1-Vol-1-Tone-and-Auto-Split.png

I'm thinking of using one of these for the controller:

https://www.sparkfun.com/products/8680?_ga=2.51768426.217494193.1501520143-551496983.1501520143

This is all good and well but it only goes upto 10K Ohms and most guitar Pots are between 250K and 500K so I would need to put something in the circuit for the soft pot to feed into, I've been looking at digital Pots that the soft pot can control but this might not be the best road to go down...

Does anybody here have any good ideas?

Cheers

 

[kellys_eye]

Is there a distinct advantage to having a touch control volume on a guitar? I would have thought it would be prone to accidental operation and mess with your performance.....

The touch pots you link to won't maintain the spot resistance value you create at 'touch' so will require some interface to measure and store this information. A small processor would suit, sending the created value to a digital potentiometer chip that would be fitted in place of the existing pots - such digital pots being available in assorted values to suit.

 

[Chris Riddell]

Its more of an experiment, I've used one before many moons ago and it was quite cool dependant on where on the body it is placed...

So I would need a chain like this Pickup>Softpot>Processor>Digital POT>Output

What processor would you go for?

 

[kellys_eye]

The processor would depend on what you're familiar with. The actual control requirement isn't difficult or processor-intensive so any of the popular platforms will work.

 

[Chris Riddell]

Okay I'll probably end up using an Arduino then also I found a few 1M ohms digital pots how do I restrict these to 500K?

 

[kellys_eye]

Probably not necessary. The volume control is a simple voltage divider (the signal is wired directly across it and the output taken from the wiper) and any value from 100k to 1M would do the job.