choices of capacitor for wiring inside a guitar

[dave_mc]

I know some of the guys on Music Radar almost blow a valve when the frequent question of PIO caps comes up, but I just go with what feels right and am happy with either the Orange Drops or the Paper in Oil

personally i just want to know the right way of it, because I'm willing to spend money for an actual verifiable improvement, but I don't want to spend money on snake oil.

that they do! personally, i don't mind what people spend their money on.

neither do i- as long as they're properly informed.

[Toe-Knee]

There have been a few comparisons done on the matter but nothing really rock solid or high quality. It's a similar argument to pots affecting the tone where in reality its the value of the pots that do.

The only way you can know for certain is to buy a bunch of caps and try hot swapping them using crocodile clips.

[WezV]

There have been a few comparisons done on the matter but nothing really rock solid or high quality. It's a similar argument to pots affecting the tone where in reality its the value of the pots that do.

The only way you can know for certain is to buy a bunch of caps and try hot swapping them using crocodile clips.

did you not see the vid i just posted. I know not everyone wants to see 3 mins of me flicking a switch :)

  its hardly conclusive but only because it only compares 2 types of capacitors.  Ok, sound quality could always be better - but you can still hear the tone of the guitar/amp pretty clearly.   I mean, they are 2 different types matched for the same value sounding exactly the same to my ears.   I think they sound different occasionally but its just me being inconsistent in attack - which is why there are 3 or 4 switches at each setting to limit that affect

the main point is that if you are going to compare capacitors it shows the best way to do it - without real time switching your ears can play all kinds of tricks on you.... even if doing a quick swap with croc clips

[Oli]

Thanks for the video, Wez! I can't really hear any difference on the speakers im using here at work-- i'll give it a listen at home to check later, but it seems a small enough difference to not be terribly concerned about. I know there's weight in the 'small differences add up to a bigger difference' argument, but there are more important areas that one can focus on in order to improve tone.

[WezV]

I would say there was no difference in the clip.   some seem to appear on the strumming parts but i know that is more down to my technique than the actual tone control - as confirmed by the next time i flick the switch back and forth

now obviously i haven't used expensive PIO caps for the clips, just two different types of the same value.  so i dont expect to convince anyone that PIO dont sound different from this clip alone.  but hopefully its enough to cast some doubt on it and convince people to try it themselves with their our favorite caps

[dave_mc]

^ yeah occasionally i heard slight differences, but I don't know if it was the same cap every time which sounded different (i wasn't paying that much attention to it :lol: ). Plus as you said, it could just be the recording or slightly different playing.

neither do i- as long as they're properly informed.

I should probably clarify what i mean here, as reading this back today it's a bit ambiguous.

When I said, "as long as they're properly informed", I meant "as long as companies aren't deliberately telling them lies to get them to buy their stuff."

Of course i'm not suggesting that people purchasing anything should have to pass an exam before they're allowed to buy anything, if people get the wrong end of the stick on their own (without prompting from less scrupulous companies or businesses) that's fair enough.

[Toe-Knee]

There have been a few comparisons done on the matter but nothing really rock solid or high quality. It's a similar argument to pots affecting the tone where in reality its the value of the pots that do.

The only way you can know for certain is to buy a bunch of caps and try hot swapping them using crocodile clips.

did you not see the vid i just posted. I know not everyone wants to see 3 mins of me flicking a switch :)

  its hardly conclusive but only because it only compares 2 types of capacitors.  Ok, sound quality could always be better - but you can still hear the tone of the guitar/amp pretty clearly.   I mean, they are 2 different types matched for the same value sounding exactly the same to my ears.   I think they sound different occasionally but its just me being inconsistent in attack - which is why there are 3 or 4 switches at each setting to limit that affect

the main point is that if you are going to compare capacitors it shows the best way to do it - without real time switching your ears can play all kinds of tricks on you.... even if doing a quick swap with croc clips

Sorry I missed that. I was posting from my phone. I'll check it out now from what you have said you have come to the exact same conclusion as I have.

[jpfamps]

In any scientific sphere, if you find an effect you then want to find a mechanism.

If caps do sound different then there can only be a number of explanations:

1) The caps are different value.

The most likely explanation. Few people measure the capacitance before fitting.

Wez's finding with the ceramic caps is interesting; ceramic caps have a poor reputation, but could this be due to their very poor tolerance?

2) The caps are distorting the signal.

Capacitor distortion can be measured in electrolytic and polyester caps. You would never use the former as tone caps. Polyester caps show a signal dependent distortion; however the effect is only measurable at the sort of signal levels you would find in a valve amp, and even then it's debatable whether this is audible.

If you use polypropylene caps then distortion is not an issue.

3) Series inductance.

This could affect the tone response, but only if the series inductance were large enough. The series inductance however is very low for caps, and this, in my opinion, is unlikely to have any audible effect.

4) Some other effect that has eluded scientific investigation.

I would put this in the unlikely category.

I think Wez hit the nail on the head with this, ie you need to measure your caps before installation.

[jpfamps]

out of the others most were within 10% and i found 4 different caps all rated at 0.02uf .  i dont think all the cheap multimeters do it but over a certain price point most have capacitance meters

Even some expensive meters don't have a capacitance measurement!

Most meters with a capacitance measurement are OK at these sort of values, although to get a truly accurate measurement requires a component bridge.

Did you ever try to get any idea of what difference in value was audible? For example can you here a 10% difference?

[Toe-Knee]

In any scientific sphere, if you find an effect you then want to find a mechanism.

If caps do sound different then there can only be a number of explanations:

1) The caps are different value.

The most likely explanation. Few people measure the capacitance before fitting.

Wez's finding with the ceramic caps is interesting; ceramic caps have a poor reputation, but could this be due to their very poor tolerance?

2) The caps are distorting the signal.

Capacitor distortion can be measured in electrolytic and polyester caps. You would never use the former as tone caps. Polyester caps show a signal dependent distortion; however the effect is only measurable at the sort of signal levels you would find in a valve amp, and even then it's debatable whether this is audible.

If you use polypropylene caps then distortion is not an issue.

3) Series inductance.

This could affect the tone response, but only if the series inductance were large enough. The series inductance however is very low for caps, and this, in my opinion, is unlikely to have any audible effect.

4) Some other effect that has eluded scientific investigation.

I would put this in the unlikely category.

I think Wez hit the nail on the head with this, ie you need to measure your caps before installation.

This is an excellent post that i agree with wholeheartedly.

I do think that value point you make is the biggest factor in what people hear. Especially in older type caps where the tolerances arent as tight

[WezV]

Did you ever try to get any idea of what difference in value was audible? For example can you here a 10% difference?

didn't consider it tbh as i was focused on finding ones of the same value.   maybe i need to do it again with two of the same type of cap with slightly different values.   i went through 6 of the plesseys to find one that matched the orange drop pretty closely

wish i still had those ceramic discs around here somewhere, but i am fairly sure i threw them in the bin after the original time i did this.

if any one wants to try my experiment without adding a mini switch see this vid
http://www.youtube.com/watch?v=92G-jw4TqS4&feature=share&list=UU8AgXWvEbsuZhlqqXR2q5DQ

he is suggesting material does make a difference but note that he never compares actual value of the caps in question.   but he shows a nice way to do the test without altering your guitar

[Philly Q]

^

That was fascinating.  But what an unbelievable geek he is to do that, and what an unbelievable geek I am to watch it.

[WezV]

^

That was fascinating.

but intrinsically flawed at the same time for not matching the caps actual value ;)

[Dmoney]

For what its worth. I use Ceramic caps in amps I build for values in the picofarad range. 500pf, 1000pf and maybe a little higher. I tend to use high voltage dipped types with very very tight tolerances. I think I prefer using those the mica caps. Compared to the little brown ceramics though they cost a lot more.

As for bigger values I like Polyester caps, at least in amps. I've given up on tone controls now though, so for me the argument is interesting but redundant. oops. Maybe its also interesting to mention that some orange drops and tubular polyester caps have an outer foil that you can wire to the point with the lowest impedance to ground so it acts like a little shield. Whether it makes an audible difference in an amp or guitar though... im not sure. I can see a difference in induced noise into a cap out of circuit using a scope though and swapping which end of the cap is grounded.

[WezV]

i am led to believe it is different in amps and pedals depending on the situation, from the same people who told me it was irrelevant in guitars