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Caps, the truth is out there.

Tim

Active member
Joined
Jul 15, 2001
Messages
1,832
Excuse me, Tim. I'm going thru a rough patch and get a bit cranky. All you say is correct. How does it apply in a guitar circuit? Where does the any frequency enter or go thru the cap? As I had posted before, I got schooled about this at Whirlwind, after I made some bold claims about how much better pio caps were in my Les Paul.

The two top engineers and designers, one, Tony was from the old original MXR andthen ART before Whirlwind. I lost my bet when we tested every type of cap, precisely measured recorded and frequency plotted the results and there was no audible or measured difference between any of the caps with the same simple old digital meter.

So I end up measuring and matching hundreds of flippin' resistors and caps and handwiring the first couple of hundred Rochester Series FX pedals. I swear by everything holy, I WAS WRONG. I am relying on the real example, shown to me and the explaination given me by very acomplished audio engineers with proven, real world experience and degrees in electrical engineering,to. And like everything I have found true, some seem to look for excessively minute, hair splitting molecular differences hat have no applications to the function at hand.

So yes capacitors are complicated and fascinating components that have real and nuanced effects, in amp circuits.

So please tell me what exactly is the sonic effect in a guitar tone circuit? What exactly can be heard between a .022 pio cap and a butt simple .022 ceramic disc in a guitar tone circuit? Really, I just need to know how our ears and expensive testing equiptment failed. 'Cause I don't have a degree, I barely understand he deep science of this and rely on what my ears tell me and what my eyes see on the frequency analysers and graphs show. I also rely on the knowledge of those more learned than myself to try and get at least a basic understanding. So was I tricked into doing a boring job by smart hucksters? 'Cause I don't see where signal goes through the cap and I could not detect any difference among any of the many different caps of all types with the exact same measured capacitence load.

Al, first I never said there was a difference or that you would be able to hear one. My first post was to just say I can see where there could be given the different constructions. IE, just because two differently built caps have the same discharge time constant (which is how they calculate it's capacitance value), they may not offer the exact same resistance to current flow at higher frequencies due to molecular differences, though I'm sure they would be close.

Then you replied, "only applicable in amps where voltage and current enter." This I disagree with because there is current generated by the pickup passing through the tone cap in the guitar. The tone pot only allows a small amount to pass through it on '10', but as you turn it down and take resistance away, more and more of the pickups signal is passing through the cap. The only current that can't pass through a cap is DC, which the pickup is not making anyway, it's all AC. For the higher frequencies, the cap is much less resistive and essentially you're shorting those high frequencies out across the pickup's terminals and they never make it to the amp and you never hear them. The low frequencies are attenuated as well by the cap but not near as much as the high frequencies are.

The resistance of a cap is 1/(2*pi*f*c) so at higher frequencies or higher capacitance values or both, the cap becomes less resistive.
 
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Triburst

Well-known member
Joined
Feb 12, 2006
Messages
4,346
I think a lot of the "unicorn rainbow" stuff happens because so many people also replace the caps when they open the cavity to replace the pots, wiring harness, or pickups. Then -surprise- they hear a difference. :##
 

Minibucker

Active member
Joined
Jan 12, 2003
Messages
6,340
The way that I understood it was that the the tone control of a guitar is essentially a low pass/high shelf filter...that the more you turn the tone down the steeper the Q/shelf, and that everything you end up hearing is what is NOT bled off to ground. So whatever's going through the capacitor isn't going to the amp (or coming out as sound), but maybe there are very subtle, micro-harmonic thingy's (since we're being so technical :laugh2: ) that aren't filtered out depending on capacitor type/material/etc. that affect what's left or the response to certain picking dynamics...as opposed to say, a constant sine wave?

Personally, I hope there isn't any difference in make/model, because then I can just pick from my extra orange drops and Mallory's from amp builds/repairs if I want to fine-tune how much I want the tone pot to take out on whatever.
 
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renderit

Well-known member
Joined
Jan 19, 2009
Messages
10,134
The way I see it is: a cap is a wall.

There are many kinds of walls.

A brick wall allows nothing to pass.

A ceramic wall is like that.

One made of oil with suspended particles does not always stop everything all the time.

Sometimes the electrons hit impurities in the oil and paper.

Other times not so much.

It happens so fast that the wall is not quite as effective.

The meter is giving us an average.

The meter is a tool.

As am i.
 

EpiLP1985

Member
Joined
Aug 11, 2017
Messages
113
The way I see it is: a cap is a wall.

There are many kinds of walls.

A brick wall allows nothing to pass.

A ceramic wall is like that.

One made of oil with suspended particles does not always stop everything all the time.

Sometimes the electrons hit impurities in the oil and paper.

Other times not so much.

It happens so fast that the wall is not quite as effective.

The meter is giving us an average.

The meter is a tool.

As am i.

As an electrical engineer, I have gone back and forth with people and re-evaluated my own opinion on this for years. Also, my other hobby is home brewing, where taste is just as subjective as tone. Whether or not there is a tone difference between caps is neither here nor there. What matters is if the player enjoys the tone, much like if the brewer enjoys the beer.

I think many of these arguments come down to intentions too. I don't think there are player to player "beefs" about who uses what but rather who charges extreme prices for caps, i.e. people can play and enjoy whatever they want so long as no one is trying to prey on, or profit unreasonably from, the sale of a cap with very subjective tone properties.

Science be damned, I currently have some off value Bumblebee's in my guitar. I have also used "off the rack" Mallory's, Orange Drops and Black Beauty mylars. Whatever works at the time and sounds best to me is what I use. Sometimes the best cap is the one you currently have installed. It's the tweaking that goofs us up!
 

renderit

Well-known member
Joined
Jan 19, 2009
Messages
10,134
I have no pio caps in my GrainFather.

But the result tastes fine.

Point taken.
 

EpiLP1985

Member
Joined
Aug 11, 2017
Messages
113
I have no pio caps in my GrainFather.

But the result tastes fine.

Point taken.

Exactly. The Modern Wiring in my Speidel Braumeister has not seemed to dull the tone of my beer when roll off the boil intensity control.
 

latestarter

Well-known member
Joined
Nov 9, 2009
Messages
4,073
Could I suggest pot taper has a perceptional (is that a word?) influence on how someone might hear a cap play out?

I know on a fish slice, which I use often for lifting eggs from my iron pan, taper is everything. Maybe there are parallels?
 
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