How to use a switch to select different resistors

[Guybrush]

Hi all

I'd like to make R9 on the MK1 Tone Vendor circuit switchable so I can choose from two different values.

Simple question - how do I do this please?

Hopefully it's a simple answer, but a basic diagram would be appreciated if possible.

Thanks.

 

[Aleph Null]

Here's How I would do it. The blue lines represent the resistor leads, the green, your wire. Using an On/On switch each resistor will be connected to an outside lug and to the middle lug, then a wire from the two outside lugs is each attached to a resistor pad on the PCB. Depending on how the switch is flipped, one of the resistors will be shorted and the other selected.

 

[pricklyrobot]

This is another way to do it.

 

[pricklyrobot]

Or, if you want to get fancy, use an On/Off/On, do a little bit of parallel resistance math (it builds character!), and have three values on tap.

 

[pricklyrobot]

Or skip the paralleling and use a DPDT On-On-On toggle

 

[Guybrush]

Thank you all. Really do appreciate it

Pricklyrobot - one thing at a time!

 

[Robert]

Here's How I would do it. The blue lines represent the resistor leads, the green, your wire. Using an On/On switch each resistor will be connected to an outside lug and to the middle lug, then a wire from the two outside lugs is each attached to a resistor pad on the PCB. Depending on how the switch is flipped, one of the resistors will be shorted and the other selected.
View attachment 110087

Agreed. This way if the switch fails (and during transition) you are left with R1 + R2, not an open connection.

 

[Aleph Null]

Agreed. This way if the switch fails (and during transition) you are left with R1 + R2, not an open connection.

True! It also means that the legs of each resistor, as well as both wires, are attached to the sturdy lugs of the switch instead of flapping around in the enclosure.

 

[pricklyrobot]

True! It also means that the legs of each resistor, as well as both wires, are attached to the sturdy lugs of the switch instead of flapping around in the enclosure.

Fair point.

Though my argument for the one I drew would be that it’s a little easier for a beginner to follow, visually and conceptually.
And you can certainly make it plenty sturdy with proper lead trimming/twisting and some strategic heat shrink. I’ve never made one that flapped

Re: switch failure, you could make the argument that a failure that results in an open circuit is better than one that results in the pedal sounding ‘slightly abnormal’, since it prompts you to immediately move to troubleshooting mode

 

[Aleph Null]

Fair point.

Though my argument for the one I drew would be that it’s a little easier for a beginner to follow, visually and conceptually.
And you can certainly make it plenty sturdy with proper lead trimming/twisting and some strategic heat shrink. I’ve never made one that flapped

Re: switch failure, you could make the argument that a failure that results in an open circuit is better than one that results in the pedal sounding ‘slightly abnormal’, since it prompts you to immediately move to troubleshooting mode

Also, true! There are multiple, perfectly good ways to do it.

 

[pricklyrobot]

There are multiple, perfectly good ways to do it.

And herein lies the beauty of amateur electron wranglin’!