Stuff you wanted to know but were afraid to ask

[lowpitch]

Here is mine thing I am afraid to ask.

What does the stand alone Klon buffer do?

Prevents the circuit after it from loading down your guitar pickups or whatever circuit preceeds it which can negatively impact tone, just like any other buffer really but it's the Klon buffer. So there's that More info on buffers: https://forum.pedalpcb.com/threads/whats-a-buffer-how-do-they-work-and-why-would-we-want-one.15244/

 

[jcpst]

Here's the portion of the klon circuit

 

[CheapSuitG]

Great answers, thank you.

Another question - Washer order for footswitch, jacks etc. I have an idea but what is standard practice?

 

[lowpitch]

Great answers, thank you.

Another question - Washer order for footswitch, jacks etc. I have an idea but what is standard practice?

Height adjustment nut if applicable, lock washer (toothed thingie), enclosure panel, flat washer, nut

 

[giovanni]

Height adjustment nut if applicable, lock washer (toothed thingie), enclosure panel, flat washer, nut

I learned this the hard way. Being mocked indirectly by folks on this forum.

 

[andrewsrea]

My question is: Why is the musician's equation = (current number + 1)?

For example: How many pedals do you really need? A: current number + 1.

Happy Friday, everyone!

 

[tegendemuur]

The first lie they teach you at school is that there are no stupid questions.

That being said, I find impedance - "resistance to current" - to be such a vague concept. Anyone here who can sort of paint a picture for my mind to grab onto? Perhaps via the liquid representations that are so very common to explain electronics? My mind just doesn't do abstractness well. Math has been a hell all my life; give me the concreteness of physics any time of the day!

 

[mybud]

The first lie they teach you at school is that there are no stupid questions.

That being said, I find impedance - "resistance to current" - to be such a vague concept. Anyone here who can sort of paint a picture for my mind to grab onto? Perhaps via the liquid representations that are so very common to explain electronics? My mind just doesn't do abstractness well. Math has been a hell all my life; give me the concreteness physics any time of the day!

https://www.techtarget.com/whatis/definition/impedance may be helpful.

 

[jcpst]

Oh I got one- I know this information is scattered around and I’ve seen some of it before.

Regarding Capacitors: In what scenarios can you substitute different types? I get that you have to consider polarity if you go from non-polarized to polarized. But what’s good for audio path, not good for audio path, etc. I’ve got ceramic, film, electrolytic, tantalum, mlcc…

 

[JTEX]

[...]But what’s good for audio path, not good for audio path, etc. I’ve got ceramic, film, electrolytic, tantalum, mlcc…

Best for audio path:

up to about 47nF: C0G ceramic, or film (film caps tend to be larger, pricier and easier to damage while soldering).
from 47nF to maybe 4.7uF: film
above that: electrolytic

I wouldn't use tantalum for audio (or anything, really). When they go bad, they tend to burn a hole in your PCB like a mini-thermite.

MLCCs using X5R or X7R dielectric can be ok for non-critical audio path use (such as guitar effects), if you know what you're doing. Their capacitance can vary a lot with the DC bias across, and also with temperature. Best used for DC filtering, switching power supplies and the like. If you do have to use them with audio (I do), make sure the voltage across them (DC or AC) is much lower than their rated voltage, to avoid distortion and loss of capacitance. They can also be microphonic, so be careful in high gain circuits or you might get squealing/oscillations.

MLCCs using Z5U and Y5V dielectrics: just say no! They're terrible.

 

[Aentons]

The first lie they teach you at school is that there are no stupid questions.

That being said, I find impedance - "resistance to current" - to be such a vague concept. Anyone here who can sort of paint a picture for my mind to grab onto? Perhaps via the liquid representations that are so very common to explain electronics? My mind just doesn't do abstractness well. Math has been a hell all my life; give me the concreteness physics any time of the day!

Resistance is like a head on collision. Impedance is how fast you have to zig and zag to get thru

 

[tegendemuur]

Resistance is like a head on collision. Impedance is how fast you have to zig and zag to get thru

Ah, I like that one!

 

[rwl]

I haven't been able to find a good explanation of why capacitors act only on certain frequencies.

I'll read something like "change C3 to 22nf and you'll get more bass". Does it work the same for caps on the audio path and to ground (I feel like I've seen similar guidance for both)? Is it the same in all circuits? Do y'all just have the capacitance to frequency memorized or are you applying a formula?

What gives?

 

[jwin615]

I haven't been able to find a good explanation of why capacitors act only on certain frequencies.

I'll read something like "change C3 to 22nf and you'll get more bass". Does it work the same for caps on the audio path and to ground (I feel like I've seen similar guidance for both)? Is it the same in all circuits? Do y'all just have the capacitance to frequency memorized or are you applying a formula?

What gives?

Caps have a "rise time" or charge time, depending on their value. When the wavelength time of a particular frequency is shorter than the rise time, that AC looks like DC to that capacitor. Caps block DC.
Edit to add, this is part of reactance. In the pedal world we don't really talk about reactance enough. And I'm not going to here. Google it muh guy/gal.

 

[spi]

I haven't been able to find a good explanation of why capacitors act only on certain frequencies.

I'll read something like "change C3 to 22nf and you'll get more bass". Does it work the same for caps on the audio path and to ground (I feel like I've seen similar guidance for both)? Is it the same in all circuits? Do y'all just have the capacitance to frequency memorized or are you applying a formula?

What gives?

This might be more info than what you were looking for, but if you read the following 3 articles, you'll have a good understanding. And you'll find the formulas.

This one explains how a capacitor behaves:

https://www.electronics-tutorials.ws/filter/filter_1.html

This one explains how to use a capacitor as a low-pass filter:

https://www.electronics-tutorials.ws/filter/filter_2.html

And this one for high-pass filter:

https://www.electronics-tutorials.ws/filter/filter_3.html

 

[Harry Klippton]

Caps have a "rise time" or charge time, depending on their value. When the wavelength time of a particular frequency is shorter than the rise time, that AC looks like DC to that capacitor. Caps block DC.

Slightly on topic here. Are there general rules for cap sizing to block DC?

 

[benny_profane]

Slightly on topic here. Are there general rules for cap sizing to block DC?

My understanding is that once the capacitor is fully charged, DC current into a capacitor stops, effectively blocking DC current.

 

[jwin615]

Slightly on topic here. Are there general rules for cap sizing to block DC?

Their voltage rating...?
I feel like this is a trap.

 

[jwin615]

Who's gonna be next to lose a finger?

 

[ICTRock]

Slightly on topic here. Are there general rules for cap sizing to block DC?

the first one is voltage rating ... can't use 16v coupling caps in your tube amp. the other consideration would be the frequencies you allow through. since this sort of discussion usually revolves around signal amplification of some sort, the tendency is to filter off some bass to prevent blocking distortion and improve frequency response