Les Paul Jr Capacitor Upgrade

Jackie Treehorn

Silver Supporting Member
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2,351
Well if you looked at the results of that test, you would see that would make you just about the only one of the many people who submitted their answers who could pick the difference vs ceramics. So you either have very special ears that can hear things that no one else can (in which case no one listening to your music could tell the difference), or you're pulling our leg.

So I repeat the request that you set up the same youtube experiment with some other different capacitor types of the same measured value (including the ones that you suggest are superior). Have someone else do the switching (so that the test is double-blind). Invite others' answers, and see if your ears are as unique as it seems, or if maybe others share your golden ears. Otherwise the rest of us who hear no difference in the video I posted are likely to conclude that you're just blowing smoke. And furthermore that there's absolutely no point in us mere mortals with regular ears preferring some capacitor types over others. ;)

If you looked at the test and results objectively, you would see that they are completely invalid. 2 tests, pick out the bumblebee, but there was no bumblebee to pick out in the second. As a result, the second test result is RANDOM guessing. So, the result, the scoring is not valid, a 50% score does not prove an inability to distinguish a bumblebee because there was only one valid question.

As to me proving my capacitor preferences, maybe I will post clips sometime. However, in my experience on the internet, people who make conclusions based on no evidence, don’t have high regard for evidence at all.
 
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disconnector

It's been swell, but the swelling's gone down.
Gold Supporting Member
Messages
1,870
Well if you looked at the results of that test, you would see that would make you just about the only one of the many people who submitted their answers who could pick the difference vs ceramics. So you either have very special ears that can hear things that no one else can (in which case no one listening to your music could tell the difference), or you're pulling our leg.

So I repeat the request that you set up the same youtube experiment with some other different capacitor types of the same measured value (including the ones that you suggest are superior). Have someone else do the switching (so that the test is double-blind). Invite others' answers, and see if your ears are as unique as it seems, or if maybe others share your golden ears. Otherwise the rest of us who hear no difference in the video I posted are likely to conclude that you're just blowing smoke. And furthermore that there's absolutely no point in us mere mortals with regular ears preferring some capacitor types over others. ;)

The Gibson Bumblebee caps are often just cheap poly wrapped in "Bumblebee" plastic. See this article - https://www.mylespaul.com/threads/historic-gibson-faux-bumblebee-caps.118027/
 

Jackie Treehorn

Silver Supporting Member
Messages
2,351
I feel the same about those who make boastful claims without evidence, too.

Me, too. All my claims are made with utmost humility, btw. In the case of the blind test, I’m not boasting, it’s simply a fact. Inevitably, a cap thread pops up, I give my opinion, someone says I’m wrong and links the test, and I tell them I already did it. I’m just trying to move the conversation on from placebo/confirmation bias. If it rubs you the wrong way, I promise to never mention it again if people stop asking me to take it.
 

d95err

Member
Messages
192
To add to the fun, in a typical RC-filter guitar tone control, the signal bled off from lowering the tone pot passes thru the capacitor to ground... the actual guitar signal that leaves your instrument does not pass thru that cap.

Rip a paper in two. Throw one of the pieces away. Can you really say that the piece you threw away did not affect the shape of the piece you kept?

A component shapes the tone just as much if it taps off signal to ground, compared to if it passes signal toward the output.


(When it comes to passive guitar tone circuits though, the capacitor type will not make any significant or auditble difference to the tone)
 

JPH118

Silver Supporting Member
Messages
4,582
Rip a paper in two. Throw one of the pieces away. Can you really say that the piece you threw away did not affect the shape of the piece you kept?

A component shapes the tone just as much if it taps off signal to ground, compared to if it passes signal toward the output.


(When it comes to passive guitar tone circuits though, the capacitor type will not make any significant or auditble difference to the tone)

That’s a great point... I guess the way I view it, the sound of the piece being thrown away would be influenced more by the capacitor it’s passing thru, than the remaining piece. Opposite regarding a CR Hipass filter in an amp, where the coupling cap passes the audible signal entirely.
 

Timtam

Member
Messages
2,845
If you looked at the test and results objectively, you would see that they are completely invalid. 2 tests, pick out the bumblebee, but there was no bumblebee to pick out in the second. As a result, the second test result is RANDOM guessing. So, the result, the scoring is not valid, a 50% score does not prove an inability to distinguish a bumblebee because there was only one valid question.

As to me proving my capacitor preferences, maybe I will post clips sometime. However, in my experience on the internet, people who make conclusions based on no evidence, don’t have high regard for evidence at all.

That's how a blinded test series works. The listeners ideally shouldn't know what the options are amongst what they are listening to. Or if they do, that expectation should be changed up. Otherwise we don't know how their preconceptions of what the result 'should' be will influence their answers. A totally ideal test wouldn't even tell people they're listening to capacitor tone circuits, since many of us obviously have a strong opinion that there won't be any differences, and you believe that there will be. And the tests should include a random number of real capacitors and some with no capacitor at all. If we already know that 3 are ceramic and one isn't, we're all listening for "the only one that isn't ceramic".

You could complement your blinded hearing tests with simple bench tests of an actual guitar tone high-pass circuit filter, using measured same-value capacitors of different types (and multiples of each type). Use a signal generator to test frequency increments within the guitar frequency range, and measure the output amplitude of the tone filter at each frequency. You would then have frequency response curves for each capacitor type, that would tell you if the capacitor types differ or not, and if they do, if it is consistently repeatable for different types, or random (eg based on old / malfunctioning capacitors, manufacturing variations, etc).
 
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walterw

Platinum Supporting Member
Messages
40,284
my tone is normally around 7-8
which implies that you probably wouldn't like the added aggressiveness of a 500k volume

now, do you like to work clean-to-crunchy with the guitar volume? if so then the stock pot is not awesome because it's linear taper, it won't respond as well with an overdriven amp. if you put an audio taper 300k (they're out there) or even a 250k audio you'd have better clean-to-crunch transition from the guitar volume.

the 250k volume would probably lead you to dime the tone knob again and might be just right. that would technically sound the same as the vintage setup with 500k vol+250k tone, but the lower-value volume has the advantage of a smoother sweep with less treble loss when you roll it down. it's how gibson should have done it back then. (i myself like all 500ks here, let that thing snarl!)

and yeah, cap composition makes no difference here at all; hell, cap value makes no difference until the tone knob is below like "5".
 

LBXPDX

Member
Messages
1,415
I’ll throw my .02$ in. Get some Mojotone vintage taper pots, buy 5 different types of caps and make sure your jack is switchcraft. The mojotone pots have a different taper, kinda in between an audio and a linear. I really dig them in my strat.
 

Jackie Treehorn

Silver Supporting Member
Messages
2,351
That's how a blinded test series works. The listeners ideally shouldn't know what the options are amongst what they are listening to. Or if they do, that expectation should be changed up. Otherwise we don't know how their preconceptions of what the result 'should' be will influence their answers. A totally ideal test wouldn't even tell people they're listening to capacitor tone circuits, since many of us obviously have a strong opinion that there won't be any differences, and you believe that there will be. And the tests should include a random number of real capacitors and some with no capacitor at all. If we already know that 3 are ceramic and one isn't, we're all listening for "the only one that isn't ceramic".

You could complement your blinded hearing tests with simple bench tests of an actual guitar tone high-pass circuit filter, using measured same-value capacitors of different types (and multiples of each type). Use a signal generator to test frequency increments within the guitar frequency range, and measure the output amplitude of the tone filter at each frequency. You would then have frequency response curves for each capacitor type, that would tell you if the capacitor types differ or not, and if they do, if it is consistently repeatable for different types, or random (eg based on old / malfunctioning capacitors, manufacturing variations, etc).

You can set up a blind test however you want. But if it’s a series...you do understand that it has to have the same subject under test. That’s my point. But you could definitely do a test where you say here are four clips, which one sounds the most different. That’s completely fine...that was not the test in question. The way that test was conducted was, we’re told there’s a switch box with four capacitors in it, 3 ceramic and a bumblebee. To pass that test, you do not have to listen for every possible difference, you can just listen for the characteristics of the bumblebee. That’s a much easier lift if you know what a bumblebee sounds like. If you then replace the bumblebee with a wire, you can no longer pick out the bumblebee, because it’s no longer in the box. You then have to guess. It’s also, not even the same circuit anymore. You’re testing the load on the frequencies below the cutoff of the filter. If you want to test that, and you tell me it’s cap vs wire, I listen for punch and volume in the lows.

So when you tabulate those two tests, it’s meaningless. They’re too different things. It’s really a good case for why tests should be double blind. Because obviously the guy conducting it thinks hey, I can just swap out the cap for a wire and who cares, it’s all the same. That’s sloppy work, in my opinion from a science perspective, but a lot of YouTube kind of straddles the line between science and entertainment or promotion.

On your further testing thoughts, I’d be more interested in finding out which metric correlates to the difference. I do have a bridge to use for testing, but haven’t spent much time getting the hang of testing esr, etc.
 

vortexxxx

Silver Supporting Member
Messages
11,405
This is only true to specific cases such as high power transfer and radio frequency applications. Neither of which are applicable to the audio frequency signal levels in a guitar. The only audible difference between two guitar tone caps is if the values are different (or one cap is faulty).
Not true. Perhaps you can't hear the difference as it is subtle. I've helped build recording studios in the past and have worked with many audio engineer pros. Many types of capacitors leak parts of the audio spectrum individually dependent on material and how they are made. I can hear it. Maybe you need to listen closely and you can pick out the differences. The high power thing has been repeated forever but it isn't true. Keep in mind many musicians have some form of tinnitus, so for many they probably can't hear the difference.
 

pipedwho

Member
Messages
1,681
Not true. Perhaps you can't hear the difference as it is subtle. I've helped build recording studios in the past and have worked with many audio engineer pros. Many types of capacitors leak parts of the audio spectrum individually dependent on material and how they are made. I can hear it. Maybe you need to listen closely and you can pick out the differences. The high power thing has been repeated forever but it isn't true. Keep in mind many musicians have some form of tinnitus, so for many they probably can't hear the difference.
Working in the telecoms industry for years we performed properly conducted clinical tests on what the real threshold of hearing is for different types of distortion and non-linearity. These effects are inaudible in anything that is not so badly designed as to amplify any non-linear property. A guitar tone circuit is not one of those. Nor are the vast majority of pre-amp and amplifier configurations.
 

vortexxxx

Silver Supporting Member
Messages
11,405
Working in the telecoms industry for years we performed properly conducted clinical tests on what the real threshold of hearing is for different types of distortion and non-linearity. These effects are inaudible in anything that is not so badly designed as to amplify any non-linear property. A guitar tone circuit is not one of those. Nor are the vast majority of pre-amp and amplifier configurations.
I disagree but I don't want to get into another cap debate. I'm pretty sure some amp builders would as well.
 

pipedwho

Member
Messages
1,681
I disagree but I don't want to get into another cap debate. I'm pretty sure some amp builders would as well.
I've been involved in many clinical tests (with extremely sensitive equipment and humans) of this stuff as part of a long career in telecommunications and audio signal processing. It's amazing how people swear they can hear something, and then suddenly can't hear it anymore in the double blind tests.

Debate isn't necessary, if you're ever in town we can set up a day of testing for the tone capacitor material. It's been years since I've done anything like this (used to do it all the time). The last thing was a cable capacitance versus bulk capacitance double blinder and that was 10 years ago. Lots of fun that day with lots of beer and a BBQ afterwards!
 

Jackie Treehorn

Silver Supporting Member
Messages
2,351
Working in the telecoms industry for years we performed properly conducted clinical tests on what the real threshold of hearing is for different types of distortion and non-linearity. These effects are inaudible in anything that is not so badly designed as to amplify any non-linear property. A guitar tone circuit is not one of those. Nor are the vast majority of pre-amp and amplifier configurations.

Studies have shown it takes a large amount of low order distortions to be perceivable however, what you left out, was that studies have also shown it takes an exponentially smaller percentage of higher order distortion to be audible.
 

Jackie Treehorn

Silver Supporting Member
Messages
2,351
I've been involved in many clinical tests (with extremely sensitive equipment and humans) of this stuff as part of a long career in telecommunications and audio signal processing. It's amazing how people swear they can hear something, and then suddenly can't hear it anymore in the double blind tests.

Debate isn't necessary, if you're ever in town we can set up a day of testing for the tone capacitor material. It's been years since I've done anything like this (used to do it all the time). The last thing was a cable capacitance versus bulk capacitance double blinder and that was 10 years ago. Lots of fun that day with lots of beer and a BBQ afterwards!

This isn’t an argument that someone with the facts would make. This is the classic internet argument brought out when you don’t like someone’s opinion, but you have no facts to refute it. “Lots of people have been wrong before, and I think you’re wrong now.”

But like Vortexx says, it’s getting tiring.
 

habatu

Member
Messages
79
If you find the sound thin then you should really change out the pickup. The pots and caps only make a small (and sometimes negligible) change in tone.
 

pipedwho

Member
Messages
1,681
Studies have shown it takes a large amount of low order distortions to be perceivable however, what you left out, was that studies have also shown it takes an exponentially smaller percentage of higher order distortion to be audible.
Yep, well above audible range.
 

pipedwho

Member
Messages
1,681
This isn’t an argument that someone with the facts would make. This is the classic internet argument brought out when you don’t like someone’s opinion, but you have no facts to refute it. “Lots of people have been wrong before, and I think you’re wrong now.”

But like Vortexx says, it’s getting tiring.
Yep extremely tiring. I'm an electronics engineer and work with audio signal processing for a living, and I've posted all sorts of technical analysis in the past on this forum and others. Back in the days of the CD player bit wars, I was involved in studies of this sort of thing that were commissioned for no other reason than to convince non-technical (or semi-technical) purchasing people that we could (or couldn't) use a different component in a properly designed system with no audible effects that might have somehow escaped our circuit modelling or physical test systems.

The only problems we found were when a circuit was poorly designed, or other circuits (sample and hold, RF, power coupling, etc). In guitar circuits, the biggest measurable effect might by ESR or leakage. And those are easily compensated for with parallel or series resistance on a decent ceramic or poly cap - and almost always are more easily compensated by turning a knob a few degrees. That's ignoring the effect that temperature has on the rest of a typical guitar circuit. In the end, any effects that might be audible in a guitar tone cap are swamped by other variables in the system. Dynamic absorption and other non-linearities and so far below the thermal noise in a guitar tone circuit that it is laughable to even consider them.

The biggest issue is when people conflate knowledge from different domains. Ie. radio frequency, power, high impedance/low impedance, instrumentation, etc. This is rampant in marketing (and therefore consumer misunderstanding), specifically in other areas like audio interconnect/speaker/power supply/guitar cabling, power amplifiers, pre-amplifiers, DACs, speakers, etc.
 




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