Total Noob Schematic Question

[ilgfo]

Hello, I want to start breadboarding some pedals before I commit to build. Example would be the Sunflower Fuzz. It has an IC section broken out at the bottom of the schematic. I am having a hard time understanding how you connect that section to the rest of the circuit since its broken out. I have a few ideas, but I simply don't want to guess, and can't find any info out there on this.

Thanks for the help

 

[Lobo da Mata]

Hello, I want to start breadboarding some pedals before I commit to build. Example would be the Sunflower Fuzz. It has an IC section broken out at the bottom of the schematic. I am having a hard time understanding how you connect that section to the rest of the circuit since its broken out. I have a few ideas, but I simply don't want to guess, and can't find any info out there on this.

Thanks for the help

Brian Wampler

 

[phi1]

This one is a bit of an odd one since the original pedal used negative voltage (common on vintage fuzzes using pnp transitors).

The IC is a voltage converter. in this case it converts +9v relative to ground into -9v relative to ground. The same chip is sometimes used to convert +9v to +18v. The idea here is that you can daisy chain this pedal with your normal power supply with other pedals and the IC converts the positive voltage to negative.

So you can wire up the chip like it's shown on the breadboard. The + and - (with circles around them) come from a regular +9v power supply. The -9v connects to the -9v at the top of the fuzz circuit and the ground connects to the ground of the fuzz circuit. Don't worry about the sw and led part when breadboaring (it's just for indicating the pedal is on).

Alternatively, you could just breadboard the fuzz circuit (skip te IC part) and use a 9v battery with the + of the battery connected to ground and the - of the battery connected to the -9v of the fuzz circuit. This won't cause issues with other effects or the amp since the battery is isolated from any other power source.

 

[ilgfo]

phi1 thank you! that's what I was assuming but wasn't confident enough. Thank you for explaining the details. Having a lot of fun with this stuff.

 

[phi1]

Always nice to see folks breadboarding! It's a great way to learn / experiment.