Les Paul Jr Capacitor Upgrade

cap10kirk

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9,509
Gibson rep said the 500k volume pot would only change how quickly it reacted to volume swells...

It could respond a little different. Even more so if you change from linear taper to audio taper or vice versa. But a 500k volume pot will also make the guitar sound brighter than a 300k pot.
 

hpharley90

Silver Supporting Member
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1,276
Do you feel it would be worth changing out pots?

I just changed the pots in my Les Paul about 6 weeks ago. Actually the whole system. I bought a prewired vintage upgrade kit from https://rs-guitarworks.myshopify.com/collections/pre-wired-kits. What I like of their pots is they buy custom made to their spec from CST. CST has a plus or minus of 20% where the custom ones are plus or minus 10%.
There is a big difference between Gibson and RS pots. I like it very much. Its more linear. Much more control and smoother.

I would leave your as is. I have a 2003 Gibson Melody maker with a single p90. The inside looks like yours. I like mine as is.
 

Chandyland

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2,522
Ok, so in that case I don’t want 500k as I am already bright enough... unless, I guess, I changed the tone from 500k to 250k like the original spec...

Man this is frustrating. Fun, but frustrating.

In my experience, you don't lose a ton of bass or mids when you up the pot value: you mostly just gain more available high end (clarity).

Honestly, I would either EQ the amp differently or ditch the Jr. entirely if it doesn't have the meat. It's really hard to get a good sound out of a P90 Jr. with an amp that's set for EMGs.

The only other decent option would be a pickup swap to something hotter than the stock P90, but I would try turning your amp's knobs first.


I just changed the pots in my Les Paul about 6 weeks ago. Actually the whole system. I bought a prewired vintage upgrade kit from https://rs-guitarworks.myshopify.com/collections/pre-wired-kits. What I like of their pots is they buy custom made to their spec from CST. CST has a plus or minus of 20% where the custom ones are plus or minus 10%.
There is a big difference between Gibson and RS pots. I like it very much. Its more linear. Much more control and smoother.

I would leave your as is. I have a 2003 Gibson Melody maker with a single p90. The inside looks like yours. I like mine as is.

This is important, as well. I've actually measured all the CTS pots I've bought from Philadelphia Luthier tools and they've never been under the rated value (this is what you want).

I've used RS pots before, too, and they're also great. Just really expensive.
 

newfiesig

Silver Supporting Member
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900
In my experience, you don't lose a ton of bass or mids when you up the pot value: you mostly just gain more available high end (clarity).

Honestly, I would either EQ the amp differently or ditch the Jr. entirely if it doesn't have the meat. It's really hard to get a good sound out of a P90 Jr. with an amp that's set for EMGs.

The only other decent option would be a pickup swap to something hotter than the stock P90, but I would try turning your amp's knobs first.




This is important, as well. I've actually measured all the CTS pots I've bought from Philadelphia Luthier tools and they've never been under the rated value (this is what you want).

I've used RS pots before, too, and they're also great. Just really expensive.
I should clarify that my amp is set up for the P90 (or at least it’s my intent). I use the EMGs on the OD channel, the crunch channel goes uneffected. It was a simple mistake of the resonance knob being pulled back too far, one of two knobs (that and presence) that is universal.

At the end of the day, I can easily tweak that one knob in between guitar changes.
 

cugel

Member
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4,755
dont change the cap it unless you want to change the value.
I always use 500k pots for p90s. Naturally a gibson rep is clueless
 

Chandyland

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2,522
I should clarify that my amp is set up for the P90 (or at least it’s my intent). I use the EMGs on the OD channel, the crunch channel goes uneffected. It was a simple mistake of the resonance knob being pulled back too far, one of two knobs (that and presence) that is universal.

At the end of the day, I can easily tweak that one knob in between guitar changes.

Ah, that makes sense. If you really want the P90s to work, I would try further tweaking the EQ, or maybe try a darker overdrive pedal.

Also, don't shy away from the tone control! A wide open bridge P90 is pretty bright, as you know.
 

newfiesig

Silver Supporting Member
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900
Ah, that makes sense. If you really want the P90s to work, I would try further tweaking the EQ, or maybe try a darker overdrive pedal.

Also, don't shy away from the tone control! A wide open bridge P90 is pretty bright, as you know.
For sure, my tone is normally around 7-8.
 

newfiesig

Silver Supporting Member
Messages
900
Ah, that makes sense. If you really want the P90s to work, I would try further tweaking the EQ, or maybe try a darker overdrive pedal.

Also, don't shy away from the tone control! A wide open bridge P90 is pretty bright, as you know.
So at the end of the day, you don’t see any utility in upgrading the cap to an orange drop?
 

cap10kirk

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9,509
Not arguing (as I have no clue), but why are orange drops so popular then? Placebo?

Marketing hype, misinformation, or simply because *insert guitar hero of choice* uses/swears by them. Personally, I buy them when I'm building a new guitar or modifying an existing guitar simply because I can get them with a tight tolerance and they don't cost much. But I only change capacitors if I'm changing the value of them, or if I'm replacing everything in the guitar just because it's easier to use new caps than to reuse old ones. Replacing that little blue .022 cap with an orange drop. 022 cap just for the sake of it isn't an upgrade in any way.
 

newfiesig

Silver Supporting Member
Messages
900
Marketing hype, misinformation, or simply because *insert guitar hero of choice* uses/swears by them. Personally, I buy them when I'm building a new guitar or modifying an existing guitar simply because I can get them with a tight tolerance and they don't cost much. But I only change capacitors if I'm changing the value of them, or if I'm replacing everything in the guitar just because it's easier to use new caps than to reuse old ones. Replacing that little blue .022 cap with an orange drop. 022 cap just for the sake of it isn't an upgrade in any way.
Fair enough. I will stick with what I have.
 

Bob Arbogast

Gold Supporting Member
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1,179
Gibson rep is wrong. The open load of a 500k vs 300k volume pot means the pickup will have a lighter static load and a therefore a higher resonant peak. This means the pickup will sound a bit brighter and you’d need need to roll back the tone slightly to compensate.
No, the Gibson rep is right. Because the 300k pot would be linear taper. A 500k (audio taper) absolutely would have a different character with volume swells.

In my experience, a 300k (linear) or an RS 280k super pot allows plenty of bright from a bridge P90. YMMV. Of course, what do I know? I have at 250k volume pot for my Tele's TV Jones Classic (neck)!
 

Jackie Treehorn

Silver Supporting Member
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2,391
Fair enough. I will stick with what I have.

Different capacitor types absolutely change the tone of the guitar, even on 10 the cap is loading the pickup. Unless you have a no load pot. When it comes to capacitors in guitars, orange drops would not be my first choice, as they don’t really sound much different than a ceramic. The ones that sound really good to me are the old paper, style, not necessarily the paper in oil, but paper Mylar. The sprague 160p for example is what usually works for me, but similar construction caps of that era/construction. To me, getting the right type of cap is crucial to having a usable tone control. The value sets the range of frequencies, which to me is secondary because if it doesn’t sound right, I’m not going to use the tone control. If the cap is good, even a .1 can have a really usable range. In a jr, without a neck pickup, I would definitely buy a lot of different caps to sample. They are cheap. The Russian mbm surplus cap is dirt cheap and sounds pretty close to the old style.

With the volume pot, you can buy a 500k, and trim it down to whatever value gels with your pickup by putting a resistor in parallel with it. So, you’d take something like a 2-5 meg pot and clip it in as a variable resistor across the volume pot, then reduce it and see if there’s a setting that jumps out at you. Measure and replace with resistor.
 

zombiwoof

Silver Supporting Member
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5,900
Different capacitor types absolutely change the tone of the guitar, even on 10 the cap is loading the pickup. Unless you have a no load pot. When it comes to capacitors in guitars, orange drops would not be my first choice, as they don’t really sound much different than a ceramic. The ones that sound really good to me are the old paper, style, not necessarily the paper in oil, but paper Mylar. The sprague 160p for example is what usually works for me, but similar construction caps of that era/construction. To me, getting the right type of cap is crucial to having a usable tone control. The value sets the range of frequencies, which to me is secondary because if it doesn’t sound right, I’m not going to use the tone control. If the cap is good, even a .1 can have a really usable range. In a jr, without a neck pickup, I would definitely buy a lot of different caps to sample. They are cheap. The Russian mbm surplus cap is dirt cheap and sounds pretty close to the old style.

With the volume pot, you can buy a 500k, and trim it down to whatever value gels with your pickup by putting a resistor in parallel with it. So, you’d take something like a 2-5 meg pot and clip it in as a variable resistor across the volume pot, then reduce it and see if there’s a setting that jumps out at you. Measure and replace with resistor.
Also, people don't seem to understand that there are different types of orange drop caps, the PS series is polyester film (mylar), and the other type (1600 or something) is polypropylene, which is supposedly more hifi sounding in some circuits. Some people prefer the polyester film type PS series, saying it has a warmer sound, more like the older PIO caps. To just say "orange drop" doesn't tell the whole story. If you believe that a cap in a guitar tone circuit makes a difference in tone, then you also have to decide which type you want. The voltage rating doesn't really matter, anything from 50-600 volts will work fine, the consideration there is size, generally the bigger the voltage rating the bigger the cap in the same type of cap.
IMO changing out the pots to ones with a 500k value that have good taper (I like the "vintage audio" (10% audio taper) and lower tolerance regarding value (1-10% tolerance) will make a bigger difference in sound. I suggest going with the original LP Junior values of 500k volume and 250k tone myself.
Al
 

disconnector

It's been swell, but the swelling's gone down.
Gold Supporting Member
Messages
1,909
Different capacitor types absolutely change the tone of the guitar, even on 10 the cap is loading the pickup. Unless you have a no load pot. When it comes to capacitors in guitars, orange drops would not be my first choice, as they don’t really sound much different than a ceramic. The ones that sound really good to me are the old paper, style, not necessarily the paper in oil, but paper Mylar. The sprague 160p for example is what usually works for me, but similar construction caps of that era/construction. To me, getting the right type of cap is crucial to having a usable tone control. The value sets the range of frequencies, which to me is secondary because if it doesn’t sound right, I’m not going to use the tone control. If the cap is good, even a .1 can have a really usable range. In a jr, without a neck pickup, I would definitely buy a lot of different caps to sample. They are cheap. The Russian mbm surplus cap is dirt cheap and sounds pretty close to the old style.

With the volume pot, you can buy a 500k, and trim it down to whatever value gels with your pickup by putting a resistor in parallel with it. So, you’d take something like a 2-5 meg pot and clip it in as a variable resistor across the volume pot, then reduce it and see if there’s a setting that jumps out at you. Measure and replace with resistor.

It's just physics brother . . . at the millivolt level of a guitar there are *ABSOLUTELY ZERO* differences between capacitors of different makes as long as their *values are the same*. Period. As long as the capacitor isn't leaky (like paper in oil) they are identical. A leaky cap isn't just capacitance - it's a resistor as well. If you like the tone of a leaky cap just get a ceramic and bypass it with a ~1M resistor. It will be the same.

What I'm saying is that the construction of the cap plays ABSOLUTELY no part in the sound of a simple LCR filter like a guitar tone cap. That's why it's called a LCR circuit - impedance, capacitance, and resistance are all that matter to that filter. Period. Mojo isn't included in the calculations, nor is any other characteristic of the capacitor at this signal level and impedance.

I used to build high speed electronic devices for a living. If you can't see any differences in a circuit at 5Ghz then no human could ever hear or even sense any difference. It's nothing more than snake oil and placebo.

Sorry to be such a party pooper but the scientist/engineer in me starts running in circles with stuff like this.
 

k tone

Member
Messages
652
For the cost do the cap upgrade. Paper in oil are nice as well. I switched the caps in my Trad Les Paul from those little tiny stock ones to Russian PIOs. I can't notice much difference but it looks killer!

As well don't go with the wiring kits. Order the parts and do it yourself. I would go with two 500k pots and a 0.022uF cap.
 

Jackie Treehorn

Silver Supporting Member
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2,391
It's just physics brother . . . at the millivolt level of a guitar there are *ABSOLUTELY ZERO* differences between capacitors of different makes as long as their *values are the same*. Period. As long as the capacitor isn't leaky (like paper in oil) they are identical. A leaky cap isn't just capacitance - it's a resistor as well. If you like the tone of a leaky cap just get a ceramic and bypass it with a ~1M resistor. It will be the same.

What I'm saying is that the construction of the cap plays ABSOLUTELY no part in the sound of a simple LCR filter like a guitar tone cap. That's why it's called a LCR circuit - impedance, capacitance, and resistance are all that matter to that filter. Period. Mojo isn't included in the calculations, nor is any other characteristic of the capacitor at this signal level and impedance.

I used to build high speed electronic devices for a living. If you can't see any differences in a circuit at 5Ghz then no human could ever hear or even sense any difference. It's nothing more than snake oil and placebo.

Sorry to be such a party pooper but the scientist/engineer in me starts running in circles with stuff like this.

The level through the cap is no different than the pickup. Can you not hear the difference in pickups, too?

Yes, it’s physics and different types of capacitors have differing electrical properties. Esr, esl, dielectric absorption, all measurable characteristics of capacitors. They are not identical. Measure them on a bridge circuit. They’re not the same.

Every inductance, capacitance, and resistance in the filter matters, even the parasitics in the capacitor.
 
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disconnector

It's been swell, but the swelling's gone down.
Gold Supporting Member
Messages
1,909
The level through the cap is no different than the pickup. Can you not hear the difference in pickups, too?

Yes, it’s physics and different types of capacitors have differing electrical properties. Esr, esl, dielectric absorption, all measurable characteristics of capacitors. They are not identical. Measure them on a bridge circuit. They’re not the same.

A guitar tone circuit is just about the simplest LCR circuit. In LCR circuits the only measurable things that count are inductance, capacitance, and resistance. None of those other things count when calculating the response curves. The calculated response curves follow the measured response curves to more places than I can reasonably type.

Unfortunately if you can't measure it - it isn't real. I'd LOVE for mojo to be a real thing. But it isn't.

I'll repeat this from the last time that we chatted about this :D

Here's the question if you're trying to sort out real truth from a sales pitch or determining if something is true or false in the real world. It's simple - can the thing that you are stating be objectively measured? That is all. Period. Full stop. The end. If it cannot be measured it's just BS ie. mojo. Mojo may make you happy (and that's fine!!) but it's not actually REAL in the real world. It's just in your head. Dozens of double blind tests in audio have found this to be true. Over and over again.

Pickups? Different magnets have totally different magnetic fluxes and permissivity. This is measurable. Different numbers of windings (you can have the same dc resistance with diff windings of diff wire gauges) and the winding pattern dramatically effect inductance and capacitance. This is measurable. Coil size and spacing have dramatic effect on how the string is magnetized and the coils are activated by the magnetic flux. This is measurable. These *measurable and objective* differences explain why different pickups sound different.

Speakers have about a gaziliion *MEASURABLE AND OBJECTIVE* parameters that effect sound transmission other than just size. Magnetic flux (measurable), free air resonance (measurable), permissivity (measurable), cone torsional strength (measurable), cone reflectivity (measurable) . . . I can go on and on. All of these are *objectively measurable*.

The human ear is the absolute worst tool for objective testing. It has been shown time and time again that differences between wires/capacitors/power cables/mojo component du jour that were "completely obvious" in previous testing were completely indistinguishable when tested in a double blind environment. And if if can't be heard in double blind testing and objectively measured then it is simply not real.

Capacitors in millivolt level guitar circuits fail the test of objective measurability. Two non-defective capacitors with the precise same capacitance will be indistinguishable because there is no measurable difference between them that can possibly have any effect audio in the human hearing range or anywhere near it. You don't get skin effects and inductance effects from capacitor construction at these sizes until you are WAAAAAAY up into the 500KHz range. This is objectively measurable. Period. Full stop. End of story.

Anyone that tells you different is trying to sell you something.
 
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