13 March 2013

Guitar Caps: Do androids dream with electrical sheeps?


This entry was already published in my old Spanish version of this blog, around April 2010. I am just revisiting it here, reviewed and corrected.

This is a subject that creates big controversies. I wouldn't like to create any kind of discussion.
Most of electronics guys will say that a cap is just a cap and that the only important thing is its capacitance that determines the cut-off frequency.
Most of people, even with an opener mind, will not hear any kind of difference.
A few people will notice small differences.

I wouldn't like to discuss anything around this subject but, just to share my personal experience and, provide you with some links that can help you to take your own decision around this subject. So, please, don't waste your time trolling me. Read, watch the videos, take your own decision and go your way.

My personal experience

When I was facing my personal special wiring project for my strato, I've swaped the typical "chew gum" cap with an Sprage Orange Drop cap, since everybody seemed to agree that such a cap was a sonic improvement respect of the stock cheap ceramic disk or those green Asian "chew gum" caps or those other brown "chew gum" caps.

I've tried it just to verify if the change of cap made some difference and, to be honest, it did it to my ears. But, the bad thing is that I've started to hear to much high end in the signal, as if the cap was cutting off most of high frequencies but left some unfiltered. In fact, it sounded me a bit with a harsher high end.

Curious about those results, I've searched Internet about opinions and experiences and, it seemed to me that the PIO (Paper In Oil) caps could be what I needed. As per other users, they seemed to sound more even balanced and with a silkier sound.
Since I didn't wanted to waste my money is expensive NOS PIO caps, that probably are out of order after so long, I've sourced some Sprage Vitamin-Q, with different capacitances, to test in several axes.

I've swapped that Sprage Orange Drop with a Vitamin-Q and, indeed, that harsh high end I was hearing was removed and, the sound was slightly silkier.

I've lately seen several people that prefers the sound of PIW (Paper In Wax) caps to PIO for single coiled guitars. Still not experienced so, I have not an formed opinion about those. I would try one in some point of time, I guess. I am always open.
I like results of PIO caps in any axe I've re-wired so, I am not in a hurry about testing other kind of caps.

My position

I know all the technical arguments against the remote possibility that two caps with exactly the same capacitance and different construction to sound (or filter) differently. I know.
But, I believe in my personal experience.

The range and sensibility of sensors for each human individual are just different.
There are people with a very special sense of smell and, they are working as highly priced specialists in the Perfumes Industry.
There are people with a very special taste and, they are working as sommeliers in Wine Industry.
There are people with very special eyes that can discover color nuances that you will never distinguish, and they are working as colorists in the Paint Industry.
There are people with very special ears, Masterizing your songs.

Also, take into account that the sensibility for high end is being gradually lost with the age. So, probably, some day I will be not able to distinguish one cap from other.

My position is as follows:
  • Just experience it with not expensive caps (Vitamin Q are around 8 Eur).
  • If you hear a difference, you should decide if the small tone difference worth the money.
  • If you don't hear a difference, you are lucky. You can buy the cheapest cap and go your way but, be respectful with people that really hears a difference. Your sensors aren't dialed in the same way.
  • If you don't hear a difference but still want to buy any kind of cap... what's wrong?. It's your axe!. Makes you happier to have an Sprage Orange Drop instead of an small ceramic disk cap?. Go ahead!.

Blind Test

Well, after a hot discussion, everybody wanted me to do a blind test.
I didn't wanted to prepare a blind test myself to demonstrate to myself what I can hear and, I recognize that, at the end, I was doubting if I was able to hear a difference. When everybody drives in the opposite direction, you are probably wrong, you know.

Fortunately, I saw a guy that made that blind test in Youtube and, I did it myself.
I just closed my eyes and started to hear each capacitor, one by one, taking notes of my impressions about each one. At the end, I wrote in my paper which one or ones seemed to me a PIO cap and which one or ones seemed to me an Orange Drop and, which one seemed to me a ceramic disk capacitor.
Those that I hadn't a clear experience, I was unable to identify but, at least they were identified as not PIO, Orange or ceramic.

Then, I watched the video again and compared my notes with the the caps demoed with full success.
So, it's clear to me. I hear the differences and, I don't mind what others that doesn't hear them can think about myself. I will not discuss about it anymore.

If you are interested on this matter, please take a look to these videos and, if you like it, try yourself to write your own notes while the different caps are being demoed (without knowing which is which). It doesn't matter if you aren't familiar with different caps, just write your impressions, if you really hear any slight difference. It's an interesting exercise.

For better results, I highly recommend you to ear those videos with a good pair of studio monitors or pro mixing headphones to distinguish the nuances.
If you don't hear any difference, don't worry, you are part of the bigger group of people. Nothing good, nothing wrong.

The patience of this guy is proverbial. The think I like more is that he simply demoes the caps, without taking any position. Good job!.

How important is the difference in tone

To be honest, we are talking here about a single drop in the cup of your tone. I would say that you will notice a higher impact just swapping your current pick (or plectro) than swapping your cap.
If you are very chasing your perfect tone, this will be just one very little add to your tone.
Probably, the slight difference that you can clearly hear while playing alone, will be lost in the mix and, practically nobody but you will appreciate the "improvement".

I am particularly very sensible to harsh frequencies and, the Orange Drop makes me to feel uncomfortable so, I am going for Sprage Vitamin-Q or Mojotone Vitamin-Q or T for my own axes.
You are the only one that can determine if a change of cap worths something for you.
  • If you are of that kind of people that calls bullshit to anything that he cannot experience by himself or that goes against well established academic standards or, against the opinion of some reverenced people, be sure that this worth nothing for you. This is bullshit, snake oil and similar.
  • If you hear differences, worth they the extra money for you?.
  • Independently of if you hear or not a difference, do you like to have certain model of cap in you axe because you find it sexy?. Nothing wrong!. It's your money. It's your axe. Do whatever that makes you feel happier.
What surprised me in discussions about this matter is that the people that was negating the possibility to hear the smallest difference with guitar caps was substituting their stock caps with Sprage Orange Drops. Trend followers?.
If you don't hear any difference, stock caps are as good as any other type for your needs, right?. So, what are you doing?. Are you being consistent with your statements?.

And, what surprised me even more is that this same people reported that they were able to hear differences in amp's caps but, negate any possibility  that I was able to hear any difference in guitar caps.
The "scientific" arguments against guitar caps, shouldn't be applied also to amp's caps?.
Crazy World!.

Well. I just wanted to share my experience with you and, the links to those videos. Your own tests will leave you in a better position to decide what to do in your particular case.


  1. Once again, thanks for sharing. I've always wondered about all the claims surrounding caps.

    1. You are welcome!.
      Thanks again for your interest.


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