How any string instrument sounds depends on hundreds of factors; even the tiniest details matter. Seemingly inconsequential things like whether the tree that the wood came from grew on the north slope or south slope of a particular valley make a difference, at least to the trained ear. Add electronics into the mix, as with electric guitars, and that’s a whole other level of choices that directly influence the sound.
To experiment with that, [Mark Gutierrez] tried rolling some home-brew capacitors for his electric guitar. The cap in question is part of the guitar’s tone circuit, which along with a potentiometer forms a variable low-pass filter. A rich folklore has developed over the years around these circuits and the best way to implement them, and there are any number of commercially available capacitors with the appropriate mojo you can use, for a price.
[Mark]’s take on the tone cap is made with two narrow strips of regular aluminum foil separated by two wider strips of tissue paper, the kind that finds its way into shirt boxes at Christmas. Each of the foil strips gets wrapped around and crimped to a wire lead before the paper is sandwiched between. The whole thing is rolled up into a loose cylinder and soaked in mineral oil, which serves as a dielectric.
To hold the oily jelly roll together, [Mark] tried both and outer skin of heat-shrink tubing with the ends sealed by hot glue, and a 3D printed cylinder. He also experimented with a wax coating to keep the oily bits contained. The video below shows the build process as well as tests of the homebrew cap against a $28 commercial equivalent. There’s a clear difference in tone compared to switching the cap out of the circuit, as well as an audible difference in tone between the two caps. We’ll leave the discussion of which sounds better to those with more qualified ears; fools rush in, after all.
Whatever you think of the sound, it’s pretty cool that you can make working capacitors so easily. Just remember to mark the outer foil lead, lest you spoil everything.
Thanks to [Eric] for the tip.
I really do not understand why audio electronics are like this, it seems on one hand you have typical consumer grade electronics with all SMD construction on a multilayer PCB built and designed like any other gizmo, and on the other hand you have these kinds of ancient components with exorbitant pricing using technologies that might have been relevant for my grandpa if he had had interest in electronics as a young adult. Hell, that capacitor probably costs more than the entire BOM for a large number of audio devices.
Instrument electronics are like this, like all instruments, due to tradition and personal preference. Unlike consumer electronics stuff like thd is desired, and tweaking through hole components is far easier than SMD.
“To the trained ear”, AKA when you “listen” with your eyes (and wallet). Funny how all that training goes away with a proper blind test.
Weird innit, it’s also funny that so often the only measurable difference is of the buyer’s bank account.
You two are confusing audiophiles, the people that buy unidirectional Ethernet cable, with musicians, the people that create music.
I’m an audio engineer that regularly deals with guitar players (making pedals) and has a particular interest in their mythology. I assure you the degree of guitar gear fetishism is on par with the audiophile crowd.
“guitar gear fetishism” I understand now, thank you.
Nah, I’ve dealt with both musicians and audiophools, some musicians will shift tens, hundreds of thousands in search of the mythical piece of kit which makes them sound like insert musician hero here and they can be just as gullible as audiophools, I’ve even encountered one or two who truly believe that certain colour effects pedals sound better than others when the internals are identical.
They at least believe in something which is there, there are millions of millions of people believing in things that are not there at all.
or is this considered trolling now? if so. please don’t be offended.
I recently read a great comparison of an audiophile vs. an audio enthusiast: An audio enthusiast uses their audio gear to listen to music. An audiophile uses music to listen to their audio gear.
Thank you for clearing that up for me.
SID chips. Just sayin…
Untrue. The average person cannot distinguish a good (actually good, 3 head) cassette deck from the source material. Cassette is objectively worse than the source in every way, but plenty of people cannot hear it. Many people also simply don’t hear the compression artifacts in an 128kbps mp3 file.
I am experienced in working with them; i can hear which one’s which it even if there is no audible noise, and am presented with 3 FLAC files numbered 1, 2 and 3 without knowing which one’s the cassette, and which ones are the source.
Same goes for musicians recognizing subtle pitch differences. Also something you can get better at with time.
That’s not quite the same now, is it?
I still have seen 0 proof that by keeping everything else the same, and only changing the wood, an electric guitar has different tone through an amp. You have to also play it exactly the same.
Prove me wrong and even then, i couldn’t care less. I can change the tone much easier with the tone knob, pickups, electronics and an amp, than changing the wood.
https://youtu.be/nrEar7dgVwI?si=WPQ-SyXSSWRr36V7
Check this out…
https://youtu.be/nrEar7dgVwI?si=WPQ-SyXSSWRr36V7
The problem with that video is he clearly does not play them the exact same way. And i think a test like that might be too hard to actually do for a human being. After you assemble and adjust the guitar with one wood and play, you are not going to even remember how the previous test was played exactly.
I do not have my headphones with me right now, so i can’t really even listen, cause my laptop speakers are the weakest shit. But i will listen to that video, when i get access to them. But my point stands. Even if i may hear differences, it just might be because he plays them differently. That has to be eliminated to be sure.
“I can hear the difference even when there is no audible difference”
Bit of a weird sentence
Seems plenty dont hear the effing joint stereo in mp3 files either. Seen 320 kbps files coded in joint. A crime against humanity if there ever was one.
What are the advantages of a “foil & oil” cap over the much cheaper type of cap?
If you label them as “vintage”, guitarists pay ten times more. Another alternative they might accept is if they’re orange coloured, in that case they should be labeled as “orange drop caps”. In other words, they don’t know much about capacitors – other than what they heard from other people who also don’t know much.
(This is, obviously, an exaggeration, there are many musicians who know a lot about electronics and are skillful at modifying musical gear, but the most vocal bunch – as with everything – is the people who know the least. Looking from the Hackaday vantage point it seems weird because we rarely get that type of enthusiasts here).
Probably it just has lower capacitance and attenuates the low and mid range more.
That’s not how an LRC lowpass works. See http://buildyourguitar.com/resources/lemme/
From my experience, there really is an audible difference with these paper in oil and wax capacitors.
Most of the measurable difference is from more parasitic inductance, and more electrical leakage from moisture ingress.
So if the difference is induction and leakage, then you probably dont need to make custom caps. You could add an inductor and a resistor to provide leakage.
Who’d have thought 2 (probably wildly) different capacitor values would have an effect on the output of a low pass filter?
Yeah. Really cool hack but he is comparing a 5nF cap to a 47nF cap here. (He measured it and posted it on his YT video description)
Haha he’s playing around twelth fret and 2-4th string. Let’s say 200-450hz
Xc for 5nF 80-160kOhm
For 47nF 8-16kOhms
I’d be more interested if the hand rolled kept it’s value for a significant amount of time than just do the sound different!
Bruh. Ya this should be in the article. Explains everything. Has nothing to do with the construction of the cap. It’s a different filter value.
That’s the point I was going to make so I’ll switch to this: The next step is to drill another hole in the knob-plate and install a variable capacitor to further tweak the sound.
But those mean scrooge guitar manufacturers who won’t give you the hip new SMDs but insist you just accept Right to Repair! Somebody call a whambulance!
You can change the sonic profile with gadjets.Though tone is in the hands as much as anything else.And the proof is in the fact that some players can grab any rat chewed piece of junk, and make it cry or sing.
Focus my friends, and just play the thing.
Snake oil caps are and have always been the better caps for hi-fi audiophile equipement and instrument amplifiers. Vegan snake oil is the preferred choice if you are wondering.
Powdered milk’s vegan right?
There’s really nothing special at all about capacitors.
If there’s an audible difference between a paper and foil capacitor or one that uses a different dielectric, I’d want to get a reading of the value of the capacitance.
The other point is if this homemade capacitor is to be used interstage with high voltage across it, I’d like to see a hipot test of a few of these.
“When you can measure what you are speaking about, and express it in numbers, you know something about it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarely, in your thoughts advanced to the stage of science.” -Lord Kelvin
Unfortunately, trying to communicate with numbers to most people is futile. The most effective way seems to be humor or sarcasm. Steve Martin said it best, “Now I’ve got a googlephonic stereo with a moonrock needle. It’s OK for a car stereo, but I wouldn’t want it in my house. ” :)
$28 for a low-voltage electrolytic capacitor? I’ve paid those kind of prices for high-voltage, high-capacity caps, but not for a 100mF, 15v piece. That’s just plain foolish.
Those coveted new old stock capacitors from the 50’s just sound so ‘special’ because the dielectric has dried out long ago and the capacitor’s capacitance has lowered. Probably ESR increased, and it probably also leaks some DC.
So, if you make your own capacitor and simulate that aging process, for instance by not having a clue what you’re doing and ending up with random capacitance and ESR, then of course your capacitor will sound like a dried-out capacitor from the fifties.
Personally I myself didn’t know until a few moments ago that the best electrolytic capacitors are only reliable up to max 10 years. And that in critical applications, you should replace capacitors every 4 years.
The capacitors in my bass guitar (Hi Leo Fender! No, it’s not a Fender, but one of your much better basses: a Music Man ;)) are probably 45 years old now. :) Never thought about replacing them. Maybe I should give that a try.
And here I am choosing the $0.65 capacitor over the $0.23 one for my tube amp.
Now if it’s a multi capacitor can and the amp is naked I will go with the chrome one from Hayseed. If it’s caged and I can’t fit the single electrolytics under the chassis or restuff the original, I’ll spend $30 for a 20-20-10-10
Yeah, that connection with the aluminum strips is not going to be reliable. If you are going through all the trouble to build your own capacitors, at least get the correct solder and flux for aluminum.
It’s also going to leak oil everywhere. Hot glue will not seal the oil in.
I bet people would pay big bucks to have “Hand Crafted, Custom Rolled, One of a Kind, Limited Edition, Capacitors” in their audiophile equipment.
This guy peeled all this down in a controlled way: https://www.youtube.com/watch?v=n02tImce3AE and you can get a full list of what doesn’t matter at 1:53.
The sound is different because hand rolling caps gives you wildly different specs and physical aberrations that impinge on the performance. Not because hand rolling is better…
“Seemingly inconsequential things like whether the tree that the wood came from grew on the north slope or south slope of a particular valley make a difference, at least to the trained ear.”
Marketing bullshit. Disappointed by hackaday for this.
Different instrument quality hardwoods matter very little on a Electric guitar in comparison to each other. (eg. Ash vs Maple vs Mahogany, etc)
The pickups, electronics, amps matter WAY more. Physical things like scale length and string tension will have more of an impact on timbre than location/type of wood harvesting.
Peddles and effects exist.
How its mixed (recording) or where it sits in the mix while playing with others
So many actual variables with electronics (parallel, series, coil splitting, phase inversion, variabilities in the pots ranges, trebble bleed, rf interference, cycle hum, grounding issues)
Post production exists
People lie, even to themselves.
Wood moisture can vary with environment even after it has been aged.
Microphones have different sized diaphragms and capture patterns, and where you mic an amp can effect recording.
The guitar industry historically has a vested interest in propagating myths to increase sales, plus exotic woods LOOK pretty.
Construction can effect timbre (bolt on neck vs glued in)
To think the human ear can tell that a tree came from the north or south side of a mountain is such a crock.
The pickups are picking up the EM field of the strings, you are playing your Amp. The wood matters more for sustain, and acoustics, but not so much you can listen to in a recording and tell what side of a valley the wood came from.
I think the bit about the “north slope” was meant a little more tongue-in-cheek that you received it.
Congrats, you’re obviously a music producer with an axe to grind.
Yeah, musicians with a lot of disposable income can spend a lot of money on pickups, electronics, etc. But to an everyday musician, the wood does matter. There is a reason that some woods are recommended for fingerboards and some for body. There are tonal differences. Also, moisture won’t
“vary” because a properly sealed wood won’t get moisture as this leads to warping. I’ve taken an acoustic guitar made of a good hardwood (not an expensive one mind you) to the beach for a weekend and barely got any damage. Also, it does matter on an electric because the acoustics (especially on good pickups) will result in different outputs.
But I DO agree with you and will add that exotic woods (like Brazilian Rosewood, for instance) are largely for cosmetic bragging rights. You don’t need $1000 of wood to make a great sounding guitar, but choices like maple, walnut, cedar do matter and make a difference if you don’t have all the bells and whistles of a ~broke~ “professional” musician.
I hear a difference. I want to quantify it though. I want the note shown through in a spectrum analyzer so you can understand what is going on with the signal. Did you reduce harmonics, did you Clip the signal, obviously there was attenuation, but what’s happening beyond the fundamental frequency you’re hearing? If you understand what is actually happening to the signal you can design around what you like and dislike without wishy washy jargon that has no real meaning beyond something to argue about like children on a playground. I love some bode plots of pickups, measurements of their field strength (stronger fields should impact how long a string vibrates and probably differently for various frequencies, hell if I know if it’s even noticable in practice beyond being measureable).