Replacing Resistor with pot VS Bending to + and -

[Tyler1144]

Usually i get a pot and make the side lugs go to + and -, but im thinking about completely removing resistors and replacing them with pots (you will no longer need the whopping 1m pots, maybe 500k at most with this method)

Has anyone ever replaced a pitch resistor before? Did it work ok/better than the other method?

[Gordonjcp]

It's a good idea to have a low value resistor in series with the pot, so it doesn't end up with a complete short circuit.

[Circuitbenders]

Has anyone ever replaced a pitch resistor before? Did it work ok/better than the other method?

??

Isn't that what everyone does? I thought that was the standard method. 

Find the pitch resistor, replace it with a pot usually of higher value and maybe stick a resistor in line so the thing doesn't crash at the extremes of pitch.

[Gordonjcp]

Has anyone ever replaced a pitch resistor before? Did it work ok/better than the other method?

??

Isn't that what everyone does? I thought that was the standard method. 

Find the pitch resistor, replace it with a pot usually of higher value and maybe stick a resistor in line so the thing doesn't crash at the extremes of pitch.

Bingo.

A good way to think of it is this:  You've got a 10k resistor in a circuit, so you replace that with a 10k pot in series with a 1k resistor.  This will go from 100% (well actually 110%) of the original value to 10% - a nice safe amount.  You could use a 22k pot in series with a 1k resistor to go from about 200% to 10% - also good.  Oh, oops - except that with the pot below 1/4 scale the circuit doesn't work!  So 1/4 scale is 4k-ish - so replace that 1k resistor with a 4k7 resistor and you're safe.

Experiment, but keep that low value series resistor.

[MAGTIG]

I've also found that it's a more smooth bend when you remove the resistor. Bending to + and - tends to make things uneven, or give the rotation "spots," when you're actually turning the knob.

What I did on my last one was leave ONE side of the resistor attached to the board (the side nearest the brain), and wired the other side of it to the middle pin on a pot. That way the pitch will always return to its original value, rather than slightly detuned (which is what often happens if you try to go to + & -). But that was on that board, you're just going to have to experiment.

Another thing I've done is put in a DPDT toggle to switch between the two circuits. I took out the resistor and soldered it to two pins on one side of the switch, then attached the two ends from the circuit board to the middle, then attached the other two pins to my pitch knobs. It works great and you can always return to the exact way it was out of the box.

I find it curious that some machines just won't bend up (as far as I know anyway). I've been working on a My Music Center keyboard and every time you try to go up, it crashes. It'll take the pitches down into the depths of hell, but even a couple semitones up and you're done.

[Tyler1144]

I've also found that it's a more smooth bend when you remove the resistor. Bending to + and - tends to make things uneven, or give the rotation "spots," when you're actually turning the knob.

What I did on my last one was leave ONE side of the resistor attached to the board (the side nearest the brain), and wired the other side of it to the middle pin on a pot. That way the pitch will always return to its original value, rather than slightly detuned (which is what often happens if you try to go to + & -). But that was on that board, you're just going to have to experiment.

Another thing I've done is put in a DPDT toggle to switch between the two circuits. I took out the resistor and soldered it to two pins on one side of the switch, then attached the two ends from the circuit board to the middle, then attached the other two pins to my pitch knobs. It works great and you can always return to the exact way it was out of the box.

I find it curious that some machines just won't bend up (as far as I know anyway). I've been working on a My Music Center keyboard and every time you try to go up, it crashes. It'll take the pitches down into the depths of hell, but even a couple semitones up and you're done.

Answer to paragraph 1: I wil do that from now on, i thought it was standard because of the way speak and spells use pitch bends, and it was my first bend project

#2 I can avoid the detune effect if i use a 1m or more (usually), but i like the overtone effect it gets if you put 200k resistance to it from + AND -. Its very noticable in the vtech apple

#3 I had also thought of using a SPDT to choose between pot control or photocell control (photocells reqiure resistors on both sides usually)

#4 For stubborn ones, use a pitch bender pedal Bending to +, or just add resistance are the 2 easiest options i can think of