# Audio Grade Electrolytics



## bhcarpenter (Feb 1, 2022)

What makes an electrolytic capacitor “audio grade”? Should I be using audio grade caps in the signal path (e.g. coupling caps)? I’m assuming it’s fine to use general purpose electrolytics for power filtering.


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## Big Monk (Feb 1, 2022)

bhcarpenter said:


> What makes an electrolytic capacitor “audio grade”? Should I be using audio grade caps in the signal path (e.g. coupling caps)? I’m assuming it’s fine to use general purpose electrolytics for power filtering.



Low ESR?


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## spi (Feb 1, 2022)

If it's a fuzz or overdrive, you don't need/want audio grade anything.


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## bhcarpenter (Feb 2, 2022)

Thanks!


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## jeffwhitfield (Feb 2, 2022)

I think the key is in using good quality caps. My understanding is that low ESR ones can help minimize noise a bit. I've been leaning towards tantalum ones lately myself. Seems they're smaller, last longer, and are low in noise anyways.


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## Bio77 (Feb 2, 2022)

I use audio caps out of early habits trying to get the best parts for my builds.  I'm not sure they matter much for pedals.  If you look through any radio forum, though, those guys are obsessed with them.  I stock up on all electros usually at Newark, if you aren't worried about an exact brand, they seem to always be blowing out something great for pennies. I stock up because shipping can be expensive. 

I do enjoy going through the schematic of each build deciding which electros should be audio.  You don't want them when they are not in the audio path, I have found generals perform better everywhere else.  Also if they go to ground, even in the audio path, I use a general.


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## vigilante398 (Feb 2, 2022)

It's a bit of a rabbit hole. I don't use audio-grade components in any pedals because my pedals aren't being used for hi-fi applications. Audio-grade caps are designed (materials, tolerances, dielectric, etc) to reduce distortion. In guitar that very often isn't a desirable thing.

Some light reading if you're in search of rabbit holes: https://passive-components.eu/audio-grade-capacitors-technology-and-applications/


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## Stickman393 (Feb 2, 2022)

I mean...eh.

I use audio grade in the signal path for values over 1 uF.  Wima has a 2.5mm poly film in 1uF that I typically use over an electro.

If you've got lots of electros in the circuit, ehhh, maybe?  It might make a difference.  Will it be noticable or not?  Meh...I don't know 

It would be difficult to do an accurate, like-for-like comparison.  One could carefully select for parts with identical values, breadboard a circuit, and hook up a switch to select back and forth between the two caps with identical actual values, and observe the results with an oscilloscope and your ears...

I would argue that adding or subtracting distortion from a guitar circuit, or any audio circuit, is going to largely amount to a subjective experience to the listener.  Tubes and vinyl aren't pristine and perfect - quite the opposite, but those end up in hi-fi nonetheless.   Honestly I don't think that any change in passives is likely to make a huge difference...but it might make some difference.  Taste is subjective, use whatever you want to use.

I personally like using hifi-type components in my builds...within reason...they tend to have thicker leads, look fancy, and leave me with a sense of satisfaction when looking over a build at the end that may be highly irrational, but fuck it, we're all irrational in certain ways.  This is just a particularly harmless way to express irrationality.


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## fig (Feb 2, 2022)

Stickman393 said:


> I personally like using hifi-type components in my builds...within reason...they tend to have thicker leads, look fancy, and leave me with a sense of satisfaction when looking over a build at the end that may be highly irrational, but fuck it, we're all irrational in certain ways. This is just a particularly harmless way to express irrationality.


Bingo. Eloquently putted.


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## Stickman393 (Feb 2, 2022)

vigilante398 said:


> Some light reading if you're in search of rabbit holes: https://passive-components.eu/audio-grade-capacitors-technology-and-applications/



This line right here has my skeptic alarm bells ringing:

_"When capacitors are mechanically loaded, some of their crystals misalign and exhibit electrical charges."_

Granted, I can't say 100% for certain that this is just babble, but here's my best attempt to translate into English:

"When capacitors are made to do physical work, their ....crystals... don't line up and show signs of voltage."

...the fuck?


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## fig (Feb 2, 2022)

Is the moon in the 7th house as well?


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## jeffwhitfield (Feb 3, 2022)

I don't think going with hi-fi / audio grade components is what's necessary. I think it's about choosing components that have good tolerances while keeping noise at bay at the same time. For a delay pedal and the like, adding noise is a bad thing. Same could be said about some overdrive and distortion pedals. Adding extra noise due to shitty quality capacitors just degrades the performance of certain circuits.

The folks at AionFX have a pretty good article on part sourcing:









						Parts Sourcing: Where to Buy What
					

After giving a general overview of what stores are out there, it’s helpful to give an overview of parts sourcing from the component perspective—the best place to buy resistors, the best place to buy…




					aionfx.com
				




They do talk a bit about MLCC's and how lower quality ones can add unwanted distortion so there's that.


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## Stickman393 (Feb 3, 2022)

Class 1 vs class 2 MLCCs, it's a thing.

Temp coefficient and microphony play into ceramics...some can have wide swings in capacitance depending on temperature.  Not so much a big deal in a climate controlled room...but I'm a big fan of cosistency.

  I haven't seen anything that would make me think twice about using a C0G in the audio path.  Honestly, those and Polypro are my go-tos.

Granted, there are gaps in my knowledge.  "Linearity" is a term that gets thrown around a lot, but I haven't yet encountered a definition that jives with me...

Then again, it's only been the last couple of months or so that I developed a better mental picture of how a capacitor behaves in a circuit.

I shoulda studied electrical theory instead of psychology and communication studies...basically railroaded myself into HVAC there.


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## vigilante398 (Feb 3, 2022)

Stickman393 said:


> This line right here has my skeptic alarm bells ringing:
> 
> _"When capacitors are mechanically loaded, some of their crystals misalign and exhibit electrical charges."_
> 
> ...


It certainly is a weird way of putting it. I'm not entirely sure what they mean by "mechanically loaded," it could be mechanically stressed or electrically loaded, or something else entirely. Either way I expect they mean that the internals of the capacitor are compromised to the extent that the materials misalign and allow arcs between the conductors.

I may be way off, but that was my understanding.


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