pitch help needed

[soflaed]

I have a toy keyboard with four large drumpads on the top. I found the resistor to control pitch and it speeds up really good without crashing. I would like for it to be able to slow down for drone like instrument.Any suggestions?

[Bogus Noise]

There's two methods to go for really. Firstly, you can remove the pitch resistor and put wires going to the pot there instead.

The second way is the voltage divider method - here you leave the pitch resistor in, and solder the wires to the pot as before, then solder a wire going from the pot's spare solder lug to ground. You can solder to the battery terminals, or as I prefer, find a ground point on the circuit board and solder to that instead.

The first method, it doesn't matter which way round the wires go to the pot, but it's important with the voltage drop method, as otherwise you get a weird pitch range. Test the connections with a couple of crocodile leads first to see which way round they're meant to go. Then you can fine tune the range with a couple of trimmers on the pot's two outside lugs. The value is not so important with a voltage divider, 100k is usually good though, but experiment if you get an odd range even after swapping the wires over.

I tend to prefer the voltage divider method, as this usually gives a nicer sweep from low to high pitches. Removing the resistor tends to give a logarithmic response where most of the pot is slower speeds, with all the high pitch bunched up at the top. However sometimes this is more pleasing for certain types of instrument - ie, more range in the slow speeds is better for controlling drones Plus you can always put a fine tune pot on there as well!

[soflaed]

I ended up replacing the resistor with a 10m. Then I put a switch to go from fast to slow. It growls now. Thanks for the replies.Don't know much about dividers. I have a problem building an oscillator. Need to practice more I guess.

[Bogus Noise]

You don't need to know much about voltage dividers at this stage, it'll come with practice, experimentation and experience. My post tells you how to set one up though... it's all about that extra wire to ground and checking you have the pitch wires the right way round. Test it out on another device and it'll make sense

[soflaed]

Thanks man. I have done the ground to pot leg on other devices and I tried it on this one but no luck. I got it done though.Thanks again. I'll have to check out your site.