Pot and cap replacement universal?

[gm2_in_co]

One of my newest toys is a Gretsch Junior Jet. I love it as is, but you know... can't help tinkering or leaving well enough alone. Looking in the cavity I notice it has 500k pots and some big dark green capacitor. I know that kind of a "standard" vintage replacement for a pbass is something like CTS 250k solid shaft pots, Switchcraft 1/4" jack, and .047mfd Orange Drop tone capacitor. My question is would the same thing apply to the Gretsch? What exactly would such replacement do to the sound?

 

[i_got_a_mohawk]

If everything was as rated (and you kept the same ratings, 500k pots and the same cap value), there wouldn't be any difference in sound at all.

In reality, you might get some changes in the tone, this is because the tolerances of these components is generally not too great.

 

[SGD Lutherie]

250K pots will darken the tone slightly. The orange drop wont do anything, since they are just caps, and sound like any other cap with the same rating when used in a passive tone control.

But putting in better quality parts is always a good idea.

 

[gm2_in_co]

But putting in better quality parts is always a god idea.

Why do it then if it makes little difference? The higher grades pots, cap, (and jack) make the electronic more durable is all?

 

[SurferJoe46]

Why do it then if it makes little difference? The higher grades pots, cap, (and jack) make the electronic more durable is all?

I think someone's thinking of better quality and the better tolerances in the gear. That's not always the situation.

Better quality is often misunderstood as higher-priced and that's not a good indicator either. Not until you get to NASA certified parts, and we all know the cost of a toilet on Spacelab.

The relative physical SIZE of the cap involved in a bass guitar isn't all that important, as we are really dealing with extremely low voltages, so the dielectric values of a larger cap aren't all that important.

Somehow - it doesn't makes sense to me to not try a different capacitor - I certainly did and just added another .1mF cap in parallel to the existing cap on my Fender Affinity and it really dropped the tone into the basement.

I like the deep-down Motown sound and it worked well for me. I later added a DPDT toggle switch to the PG for the times when I wanted to go brighter in sound and yet have the ability to drop it back as needed.

In spite what the electronicalist nay-sayers might pop off with - it works even though it might be outside their experience and good engineering knowledge to see the benefits of what I did.

I left the tone pot alone and just modded the capacitor, that's all.

 

[SGD Lutherie]

I think someone's thinking of better quality and the better tolerances in the gear. That's not always the situation.

Better quality is often misunderstood as higher-priced and that's not a good indicator either. Not until you get to NASA certified parts, and we all know the cost of a toilet on Spacelab.

Some import instruments use VERY low quality parts. This is not to say that Gretsch did that. But look in some low end Fenders and real low end stuff like SX. Those parts wont last long. I know because I have to replace them on a regular basis. These are electro mechanical parts, jacks, pots, switches, etc., so they have to be robust. Also cheap pots often have bad tapers.

The relative physical SIZE of the cap involved in a bass guitar isn't all that important, as we are really dealing with extremely low voltages, so the dielectric values of a larger cap aren't all that important.

I agree, a cap, is a cap, is a cap. As long as it is in the tolerance listed it will sound like any other cap of the same value. Cheap ceramic caps are often way off from their listed value, but otherwise they wont sound different for a tone control.

Somehow - it doesn't makes sense to me to not try a different capacitor - I certainly did and just added another .1mF cap in parallel to the existing cap on my Fender Affinity and it really dropped the tone into the basement.

I like the deep-down Motown sound and it worked well for me. I later added a DPDT toggle switch to the PG for the times when I wanted to go brighter in sound and yet have the ability to drop it back as needed.

Yeah, changing caps is fun. I use .02 and .047µF caps in my basses.

But you know, that's NOT what Motown bass sounds like. They are not cutting out all the treble at the bass, though it has been EQd later. You gotta have some mids and stuff in there to hear the attack.

Listen: Link Removed (that's the real track)

In spite what the electronicalist nay-sayers might pop off with - it works even though it might be outside their experience and good engineering knowledge to see the benefits of what I did.

I left the tone pot alone and just modded the capacitor, that's all.

What nay-sayers? That's a very common mod. I use push pull pots to do it. Some people use a rotary switch with a number of caps.

 

[SGD Lutherie]

Why do it then if it makes little difference? The higher grades pots, cap, (and jack) make the electronic more durable is all?

Cheap parts often break down.

If you like the tone of the bass now, don't change the pot values or cap values, because that will change the tone. You can do multiple caps though.

 

[SurferJoe46]

Some import instruments use VERY low quality parts. This is not to say that Gretsch did that. But look in some low end Fenders and real low end stuff like SX. Those parts wont last long. I know because I have to replace them on a regular basis. These are electro mechanical parts, jacks, pots, switches, etc., so they have to be robust. Also cheap pots often have bad tapers.



I agree, a cap, is a cap, is a cap. As long as it is in the tolerance listed it will sound like any other cap of the same value. Cheap ceramic caps are often way off from their listed value, but otherwise they wont sound different for a tone control.



Yeah, changing caps is fun. I use .02 and .047µF caps in my basses.

But you know, that's NOT what Motown bass sounds like. They are not cutting out all the treble at the bass, though it has been EQd later. You gotta have some mids and stuff in there to hear the attack.

Listen: Link Removed (that's the real track)



What nay-sayers? That's a very common mod. I use push pull pots to do it. Some people use a rotary switch with a number of caps.

I'm really happily surprised at the pots on even my Affinity Squier bass - as they are now 13 years old and they are still noiseless, accurate (as far as I can tell) and they don't bend, bag or sag at the knees. So far I may have been very fortunate, but it's all good to this time.

I did have to change out the jack and the pups though - they just got weak after those thirteen years. So much for quality control, huh?

There have been some who said that the cap doesn't do anything to the tone - and although that may be true in a very altruistic sense, aurally it is not so.

What I have wondered about is the cause/effect of the cap-change and even having a cap there in the first place.

Someone who may have been somewhat mistaken in theory said it was like the capacitive discharge caps in the boom boxes on the street cruisers with the killer bass coming from their cars. The cap provides a store house for the energy and it is discharged when the tone or freq is reached again, kinda like adding a little charge to the perceived output of the pups when that note is struck.

Others just say it clips the highs and leaves the lows alone to take over the small voltages that the p'ups can generate when they are magnetically-field cut and therefor induce a voltage to the amp. Is that understandable?

At least, even if the theory may be convoluted, the SUPPLEMENTAL CAP/TONE effect is instantaneous and somewhat dramatic if you get it right.

Somehow I accidentally struck it right.

 

[SGD Lutherie]

I'm really happily surprised at the pots on even my Affinity Squier bass - as they are now 13 years old and they are still noiseless, accurate (as far as I can tell) and they don't bend, bag or sag at the knees. So far I may have been very fortunate, but it's all good to this time.

I did have to change out the jack and the pups though - they just got weak after those thirteen years. So much for quality control, huh?

That's good. I also have some cheap pots that have held up over the years, including some from Radio Shack that lasted like 20 years.

But things are different now, and some of the newer parts are quite cruddy.

But you can get quality pots that are not much more than $5.

There have been some who said that the cap doesn't do anything to the tone - and although that may be true in a very altruistic sense, aurally it is not so.

What I have wondered about is the cause/effect of the cap-change and even having a cap there in the first place.

My point was that a poly film cap and a paper and oil cap that are both rated the same, say .047µF, will sound the same in a passive tone control on a bass or guitar. People spend a lot of money on "exotic" caps swearing they sound different, but they all function the same in this situation.

Now when used in an amplifier, then you might hear the difference.

Someone who may have been somewhat mistaken in theory said it was like the capacitive discharge caps in the boom boxes on the street cruisers with the killer bass coming from their cars. The cap provides a store house for the energy and it is discharged when the tone or freq is reached again, kinda like adding a little charge to the perceived output of the pups when that note is struck.

Others just say it clips the highs and leaves the lows alone to take over the small voltages that the p'ups can generate when they are magnetically-field cut and therefor induce a voltage to the amp. Is that understandable?

At least, even if the theory may be convoluted, the SUPPLEMENTAL CAP/TONE effect is instantaneous and somewhat dramatic if you get it right.

Somehow I accidentally struck it right.

When used in a tone control, the caps acts like a second order low pass filter and shunts high frequencies to ground. The value of the cap determines where it starts rolling off the highs, and the impedance of the pickup and value of the pots also fits into the whole equation.

So what you did was increase the value of the cap in the tone control and rolled off more high end.

 

[acebase62]

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Great info on capacitors with pictures.

 

[i_got_a_mohawk]

The relative physical SIZE of the cap involved in a bass guitar isn't all that important, as we are really dealing with extremely low voltages, so the dielectric values of a larger cap aren't all that important.

Somehow - it doesn't makes sense to me to not try a different capacitor - I certainly did and just added another .1mF cap in parallel to the existing cap on my Fender Affinity and it really dropped the tone into the basement.

In spite what the electronicalist nay-sayers might pop off with - it works even though it might be outside their experience and good engineering knowledge to see the benefits of what I did.

I left the tone pot alone and just modded the capacitor, that's all.

What we "nay-sayers" are saying, is that different types of caps, don't make a difference. Not talking about different ratings, which is where you went. Changing the capacitance will have an impact, I don't think anyone has ever said otherwise.

Adding a switch where you stick your 0.1uF (I'm assuming you mean this and not a 0.1mF cap, 0.1mF = 100uF) cap in parallel with the cap that was already there (I'm guessing it was a 0.047uF?) is going to give you the equivilant of a 0.147uF cap which is going to give you a great dub tone).

 

[i_got_a_mohawk]

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Great info on capacitors with pictures.

Poor cap info there. Just more people perpetuating snakeoil claims.

 

[acebase62]

Poor cap info there. Just more people perpetuating snakeoil claims.

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The guy has been around a while and knows some stuff, so show some respect.

 

[i_got_a_mohawk]

Why should I respect someone who is perpetuating false information?

Get a pile of different types of cap, all actually rated at the same capacitance (not just going by the number printed on it), and switch them in and out, there is no difference.

 

[acebase62]

Some people with years of experience might disagree with you, but no need to call people liars on this type of forum. Dave will go out of his way to provide detailed manufacturing information and pictures which might be helpful to some.

Brother Dave says he can hear a difference with different caps, some say no way.

Feel free to contact him if you wish.

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Best wishes.

 

[mid_life_crisis]

Different designs of caps store and release energy differently. All the ones with the same rating may store the same amount of energy, but if you were to watch the signal on an o-scope, you would see that they react differently. Some store energy faster than others and release the same way, this faster reaction time will make them sound different. Some release (or store) energy in what looks like a curve as their threshhold is reached, some are more linear. To someone with a sensitive ear, different styles of caps could sound very different indeed.
As far as Bass electronics are concerned, I have no idea what would be best, but they could sound different.
By the way, I was an electronics technician doing bench work for many years if anyone wonders where that comes from.

 

[SGD Lutherie]

As far as Bass electronics are concerned, I have no idea what would be best, but they could sound different.

In this context they don't sound different. People have done blind tests in the past, and no one could tell the difference between caps, as long as they were closely matched in their capacitance.

In an audio path, like an amp, then you would hear it.

But I like using good caps and generally use the little yellow metallized polypropylene film caps. The orange drops are also good, but people hype them up as something special. They look nice though.

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[SurferJoe46]

In this context they don't sound different. People have done blind tests in the past, and no one could tell the difference between caps, as long as they were closely matched in their capacitance.

In an audio path, like an amp, then you would hear it.

But I like using good caps and generally use the little yellow metallized polypropylene film caps. The orange drops are also good, but people hype them up as something special. They look nice though.

[Invalid or Expired Link Removed]

I think you nailed it there. The 'appearances' of a special cap just for 'bass guitars' is a pile of Bandini.

It's like some of the foods I prepare - most people eat with their eyes and they miss some really great culinary delights that way.

If someone buys a cap for a tone pot in a guitar because it's 'special' - they are just buying on sight, not technical values.

* Yeah - I meant mF, no uF.

 

[SGD Lutherie]

* Yeah - I meant mF, no uF.

Same thing... mF, µF, mfd.

 

[i_got_a_mohawk]

Same thing... mF, µF, mfd.

mF = millifarad (1x10^-3 Farad)
µF = microfarad (1x10^-6 Farad)


I can understand some confusion as I have seen MFD (all cap letters) used to represent microfarad.