I'm looking to build the Stone Age Distortion (Skeleton Key), but I realised I only have 1.6M resistors on hand, would it make much difference here?

[kylewetton]

There's four of them in this circuit, https://docs.pedalpcb.com/project/StoneAgeDistortion-PedalPCB.pdf

How much difference do you think that would make?

 

[Nostradoomus]

None

 

[kylewetton]

Thanks, so I can understand and learn, can you explain why, are they all voltage splitters?

 

[hamerfan]

Its a difference of 6 percent. My carbon film resistors even have 5 percent.

 

[giovanni]

There is one 1.5M pull down on the input whose value is not super critical since its job is to drain current to ground to avoid floating voltages. Two of them are used to connect to Vref to avoid grounding the signal where the value is again not important: their job is to have a tiny current flow so the voltage is the same as Vref without grounding the signal. The last one is in the IC feedback loop where a 6.7% value difference won’t matter much given that other components may have higher tolerances.

 

[bleepbloopboop]

that circuit does appear to be kinda messy tho. I hope someone more knowledgeable will correct me if what im saying is wrong, but i dont really see the point in using R2 and R3, especially considering the Noise R2 might add. I also dont really understand the reason for C2 to be there (maybe some kinda low-pass against high frequency stuff?) The first buffer also just introduces more unnecessary noise, as the following stage should be sufficient. Then again im still a beginner so what im saying might be utter nonsene...

 

[giovanni]

R2, R3 and C1 may be part of a filter which is probably important to the tone of the pedal. A few more resistors won’t add significant noise compared to what the clipping will do to the signal. I think. I’m not familiar with this circuit.

 

[bleepbloopboop]

hm to me the input stage just looks weirdly overcomplicated. I did a quick sim of it as well and it really just seems to be a really high tuned low pass filter (cutoff frequency is above 40k). Anyway i dont wanna hijack this post, was just curious haha

 

[manfesto]

The last one is in the IC feedback loop where a 6.7% value difference won’t matter much given that other components may have higher tolerances.

Even weirder, that one (R9) is in series with a comparatively tiny 47K resistor (R8) to set the gain, the difference between 1.5M and 1.547M is going to be *super* marginal?

Wonder why they did that.

 

[bleepbloopboop]

Even weirder, that one (R9) is in series with a comparatively tiny 47K resistor (R8) to set the gain, the difference between 1.5M and 1.547M is going to be *super* marginal?

Wonder why they did that.

Maybe to make calculations for the gain "easier" in regards to R7. Which would still be really weird.

 

[bleepbloopboop]

Im not sure what the point of C10 is either. Its in series with C12 anyways.

 

[giovanni]

Even weirder, that one (R9) is in series with a comparatively tiny 47K resistor (R8) to set the gain, the difference between 1.5M and 1.547M is going to be *super* marginal?

Wonder why they did that.

Yeah I don’t get that either.

 

[Nostradoomus]

This is a bad circuit to learn anything on, OP