How does this tone control work?

[almondcity]

I'd like to try to modify this, what components should I be looking at?

 

[maertz13]

that's the DOD classic fuzz, right? I've never seen that broken down, so I'm also curious

 

[JohnnyCreepy]

I'd like to try to modify this, what components should I be looking at?

To say what to look at, please define what kind of change you’re aiming to? Less brite or more everything?

that's the DOD classic fuzz, right? I've never seen that broken down, so I'm also curious

That’s tone circuit in the NFB partion of an operational amplifier stage.

R12 ratio to two 3.3Ks parallel with pot between sets gain and pot setting also affects low freq content passing to gnd through C11 and C8 via C7. C7 reduces tone pot scratchiness. C5 passes high freq back to -input and reduces treble content.

Feel free to fix me if I got something wrong.

For getting it familiar, throw your remains to The Boneyard.

Thread 'Opamps for Dummies - part 2'

Sep 25, 2023

Part 2 deals with the topic of how opamps are used in pedal circuits.

There are four basic building blocks made from opamps and used in pedals. Buffer; Amplifier; Limiter; Filter.

We'll use examples from the Friedman BE-OD since it contains all four building block types.

Here's a unity gain buffer. We use negative feedback from the output (pin 7) to the inverting input (pin 6) to control the gain. Since we have 100% feedback, the gain is unity. We use a buffer when we need a building block with high input impedance, low output impedance, flat frequency response and 0dB gain. It...

• Chuck D. Bones
• Replies: 21
• Forum: Chucks Boneyard

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• 
• 

 

[almondcity]

To say what to look at, please define what kind of change you’re aiming to? Less brite or more everything?


That’s tone circuit in the NFB partion of an operational amplifier stage.

R12 ratio to two 3.3Ks parallel with pot between sets gain and pot setting also affects low freq content passing to gnd through C11 and C8 via C7. C7 reduces tone pot scratchiness. C5 passes high freq back to -input and reduces treble content.

Feel free to fix me if I got something wrong.

For getting it familiar, throw your remains to The Boneyard.

Thread 'Opamps for Dummies - part 2'

Sep 25, 2023

Part 2 deals with the topic of how opamps are used in pedal circuits.

There are four basic building blocks made from opamps and used in pedals. Buffer; Amplifier; Limiter; Filter.

We'll use examples from the Friedman BE-OD since it contains all four building block types.

Here's a unity gain buffer. We use negative feedback from the output (pin 7) to the inverting input (pin 6) to control the gain. Since we have 100% feedback, the gain is unity. We use a buffer when we need a building block with high input impedance, low output impedance, flat frequency response and 0dB gain. It...

• Chuck D. Bones
• Replies: 21
• Forum: Chucks Boneyard

• 
• 
• 

I want more of a scoop. I'm assuming messing with C8 and C11 will do some of that. The taper also doesn't have much change between roughly 9 and 3 o clock, it's all bunched up at the extremes.

 

[phi1]

It’s not the same, but kinda similar to the Tube Screamer, which uses a W taper to help get some chances on the middle area.

You can try messing with this filter some for a mid scoop, worth a try. but there’s nothing structurally set up to cut mids, like a notch filter as is. If you really wanted that, you could add a big muff tone circuit somewhere, probably before the volume knob so you can add more gain in that second op amp stage to recover it.

 

[phi1]

It’s not the same, but kinda similar to the Tube Screamer, which uses a W taper to help the sweep on the middle area.

You can try messing with this filter some for a mid scoop, worth a try. but there’s nothing structurally set up to cut mids, like a notch filter as is. If you really wanted that, you could add a big muff tone circuit somewhere, probably before the volume knob so you can add more gain in that second op amp stage to recover it.