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Ceramic caps versus Oiled caps????


duane v

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This topic keeps resurfacing again and again...:-)

 

Some say that the PIO are the best thing..the holy grail of tone that the earlier LP had.

Others say it is a lot of horsefeathers and it doesn't matter what tone cap is used...

but try to convince anyone with '59 or early LP to replaced those bumblebees with any

old cap polyestere or ceramic ....they would think you're nuts!...bumblebees give the

Gibson LP that "sweet tone".

 

There seems to be enough of an interest that there have been some RI( re-issues) of these, made

in either China or the former soviet bloc countries, so the RI prices are not as exorbitant

as some of the NOS bumblebees, or sprague black beauties/vitamin Q..other PIO types.

 

The most cost effective cap you can use is the Sprague Orange Drop which is a polyester.

 

Lab testing is about the only way you can probably see or hear any differences..even

then, it's difficult to detect the slight difference in the way the tone cap is used in

the guitar circuit.

http://www.skguitar.com/SKGS/sk/CapTest/CapTest.htm

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Thanx for the response fellas...

 

The conversation came up at work today with a colleague that has 10 Les Paul's (vintage and newer). And he switched all his caps to these bumblebee things, and he swears by them. However, I spoke with our resident Electronic Engineer, and he said all things being equal, any tonal difference created by a capacitor can easily be addressed through any amplification mechanism (what ever the hell that meant)...... In other words, if the capacitor is in good working order, don't bother.

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Thanx for the response fellas...

 

The conversation came up at work today with a colleague that has 10 Les Paul's (vintage and newer). And he switched all his caps to these bumblebee things' date=' and he swears by them. However, I spoke with our resident Electronic Engineer, and he said all things being equal, any tonal difference created by a capacitor can easily be addressed through any [b']amplification mechanism [/b](what ever the hell that meant)...... In other words, if the capacitor is in good working order, don't bother.

 

I think what he could have meant is that most guitar amps, have a bass/mid/treble and in

some a presence control, so you can set the equalization of the tone that you like anywhere

you want. Bumble bees are a bit of myth on guitars. like long tenon vs short tenon..

etc...if you have paid big bucks for a vintage guitar, then you want the vintage parts

in it.

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Also boils down to what is 'more authentic'. When Gibson built the 59 LP's they didn't use vintage components they used brand new, whatever they could get for the right price that did the job.

 

Therefore what gives the more authentic sound - a 59 LP with the original caps. pots, pups, etc or a 59 with new spec components which are to 59 specs? (Ignoring the fact that the wood that the 59 was made from is now 50 years older)

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PIO caps have a higher Q factor than ceramic capacitors. A capacitor and a passive guitar pickup form a resonant tank circuit. So, you can not only hear the difference but the difference in caps can be scientifically measured. (Yes, I am an Aerospace Metrologist and have tested caps and resistors for their behavior in AC circuits.)

 

Duane Allman preferred Sprague ceramic caps in his guitar because of the particular resonant peak (cocked wha sound) that he got with the tone rolled off. I personally prefer paper in oil, with Sprague bumble bees at the top of the list. I find many usable settings throughout the tone pot that I don't get with other types. It's like having several different guitars.

 

Gary

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I'm not an aerospace meteorologist..

and the only test equipment I have is my ears and some sprague OIP caps on the way...022 and .047

which I will compare in my guitars and report.

 

 

So until then,

I believe everybody.

 

TWANG

but I like polys.. sprague and mallorys.

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all i know is that after i replaced all the electronics, with a pre-made pot setup, and 2 '57 classics, i now have a whole new guitar. i asked the guy i got the pots kit from, bcsguitars.com, why the pots kit with the paper in oil caps cost more. he told me they were much better than the ceramics. the price was negligible, so went with the pio caps. i've only ever known the orange drops from my old sg. this epi les paul is now the balls! earthy tones, and now i play with the tone pots for different sounds, which i never did before. try both, and see for your self, but i'm oil in paper from now on

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PIO caps have a higher Q factor than ceramic capacitors. A capacitor and a passive guitar pickup form a resonant tank circuit. So' date=' you can not only hear the difference but the difference in caps can be scientifically measured. (Yes, I am an Aerospace Metrologist and have tested caps and resistors for their behavior in AC circuits.)

 

Duane Allman preferred Sprague ceramic caps in his guitar because of the particular resonant peak (cocked wha sound) that he got with the tone rolled off. I personally prefer paper in oil, with Sprague bumble bees at the top of the list. I find many usable settings throughout the tone pot that I don't get with other types. It's like having several different guitars.

 

Gary

 

[/quote']

 

Gary is right. You can hear the difference because of the differences in tolerance and response of different caps.

 

A capacitor has an inverse response to frequency in that the larger the cap, the lower its resonant freqency. A tone control is an RC network that allows you to control the resonant frequency of the guitar as you roll the pot through its travel. This is, in effect, a passive wah wah circuit.

 

Since the tone control varies the resonant frequency of the circuit, you can negate some of the effects by using your amp tone controls to restore gain in particular frequency bands. A frequency equalizer will do it better since it allows you to create 'notches" of peak gain.

 

The formula for a cap's resonant freq is 1 / 2piFC where F=freq and C=capacitance. If a capacitor was a true linear device, you could plot the points on a line graph by inserting different values for F and see the results. The reality is that every cap will have its own variances and the graph will be slightly different for each one.

 

There will be a rolloff (sudden drop in response) in a tone control and there will also be peaks in the circuit that we refer to as sweet spots. Experimentation is the only way to get the right sweet spot.

 

A technical explanation of the above can be seen here, complete with graphs for different values of R and C to display different values of Q.

 

http://terrydownsmusic.com/technotes/guitarcables/guitarcables.htm

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I'm not an aerospace meteorologist..

and the only test equipment I have is my ears and some sprague OIP caps on the way...022 and .047

which I will compare in my guitars and report.

 

 

So until then' date='

[b']I believe everybody.[/b]

 

TWANG

but I like polys.. sprague and mallorys.

 

Sure, but don't trust your ears Twang...everybody's ear is different. Your hearing

deteriorates with age. I gotta be down at least 40db at 8000hz.

 

The only true test is to take a sinewave sweep generator, set it to send out a burst

of 50hz to 8000hz into a load that is your 500k tone pot and the selected cap of interest.

and hook a audio analyzer to that. That will tell you how each cap performs under

actual circuit conditions. After all, there is nothing particular or magical about

a non polarized capacitor..two foil plates to hold an electrical charge separated

by a dialectric such as paper, mylar, ceramic or paper+oil. The capacity (value of

the cap) has more to do with anything than the construction.

 

Now if these beeswax/PIO caps had some real mojo in them..then maybe, but I

doubt it. Gibson used the PIO back in the 50s and possibly early 60s until

the PiOs were stopped being produced by Mallory/Sprague and new types were

introduced, such as the Orange Drops. Gibson started to use them in the mid

60s because I saw some Gibsons with them on back then. The tone circuit is

just a frequency shunt to ground...I don't believe in the 'Q factor' here. It's

just a variable R/C time constant..the lower the R setting, the less treble is

available from the output of the selected pickup coil ,because the capacitive

reactance is greater and more treble is rolled off as the pot value gets closer

to O.

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My LP has the orange drops in them........

 

One more question..... Why the big steel bulb casing for the output jack???? My 2008 LP Jr. output jack doesnt have that

 

Are you referring to a metalic tubular jack (flush mount jack) that has a round face

visible and the locking nut on the inside of the jack plate? It's just a shielded

version/design of a guitar jack.

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Yeppers!!!

 

I noticed this when I was at my Luthier picking up my hardware, he was cleaning out the electronics...... So why and when did Gibson stop doing this??? Or is this feature still on the current LPC's.....

 

Sorry for so many questions, it's only up until recently I became interested on the inner workings of guitars

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Duane V,

 

You and I are in the same neck of the woods. PM me your address and I will mail you a pair of .022mfd PIO caps for free. Then, you can see if you like them. =P~ I have a lot of Tropicaps that are pulls but are tested, good and have plenty of lead. Do that and the Gibson 50's wiring mod on your guitar and you will be good to go.

 

Best regards,

 

Gary

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Thanks Gary

 

I'll send you a PM......

 

My pal at work is one hell of a guitarist' date=' and he wouldn't tell me something that wasn't so...... so I'll give it a shot[/quote']

I'd like to hear your evaluation of the PIO caps when you get them installed. Listen to your guitar with ithe Orange Drops, make the change and check that the guitar and amp volume settings are the same after you switch over. It's a fact that if a listener hears two sound sources and one is a bit louder, it is perceived to sound better and I think that's what happens in a lot of these cases where guys think they hear a difference. I'd try it, but it's too much effort (for such little reward, I've heard) to do this to my Casino.

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Ok, yous guys that are going to evaluate tone caps..be fair and do them all..here is a list of caps

you should try. Don't forget that there are 2 pages of these tone caps...pg2 has

the micamold tropicaps.

 

I haven't tried the Mullard "mustard" caps, but if your LP doesn't "cut the mustard", then

replace the oems with "mustard caps". The Mullard tropical fish are also very good. These are

aged caps in cool wine cellars that over the years have "formed" to produce a very rich tone.

Don't forget Jupiter genuine beeswax caps as well...the bees spent a lot of time producing the wax

that is used in potting your pickups (20% beeswax/80% parrafin) and having those vintage caps

in your guitar will match the Pafs with the "aged" Alnico II magnets.

 

Aging the magnets and PIO caps is a bit like aging blue cheese..carefully in oak casks, in cool cellars..

then charge a fortune for them..because of that ..er..secret process, which gives your LP that

special "MoJo".

 

So without further adieu..here is the list of desired tone caps to try guys..I hope I haven't missed any.

 

http://stores.shop.ebay.com/AudioGrade__W0QQ_armrsZ1QQ_fsubZ18166828

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Guys, to a certain extent, a cap is a cap.

 

Any passive component possesses three characteristics--resistance, capacitance, and inductance. Unless you have VERY long leads, inductance and series resistance in a cap should be negligible. That leaves capacitance and shunt resistance across the capacitive plates. Shunt resistance is related (inversely) to quality of the dielectric (or insulator) used to separate the capacitive plates. The higher the shunt resistance, which bleeds charge off the plates, the higher the 'quality' of the capacitor.

 

But for the small values used in guitar tone circuits, it doesn't make that much difference. Since you don't have large capacitive surfaces, there is not a lot of dielectric area and hence opportunity for shunt resistance to develop. Polyester caps won't break down over time, so they're a pretty good bet. Oil-filled capacitors are some of the oldest designs around (before more-advanced synthetic materials were available), hence their mystique. Oil-filled capacitors WILL break down over time and develop increased shunt resistance--but we're probably talking 20 to 50 years.

 

Now, you might indeed notice a difference when you change caps in your guitar, but that is more likely because the tolerances in the two types of caps differed so that you actually ended up changing the value of the capacitance in your circuit significantly.

 

So, for the most part, you are wasting your time changing the caps. You'll certainly have more effect changing the pickups, and better quality pots will give you smoother action and less "scratchiness" in your sound.

 

I'm an electrical engineer, but I don't play one on TV. ;-) Cheers.

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So' date=' for the most part, you are wasting your time changing the caps.

 

I'm an electrical engineer, but I don't play one on TV. ;-) Cheers.[/quote']

 

that's basically what our Electrical Eng. pretty much stated.... However if these guys are hearing a difference, I've gotta give credence to that as well.

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So far everybody is right... but then who is wrong? Shunt resistance and capacitive reactance, PIO aging

and breaking down in 40-50 years making those original PIO in the '59 LP true vintage, worth more than

their weight in gold? Lets face it, most of us aren't going to be around in 50 years from now..

to hear the tone coming out of these PIOs, so time is of the essence. Most good capacitors for use in

guitar tone circuits can be perceived as blended scotch whiskies (Haig or Pinch), good..but 15 yr old single malts, made

of reserve stock, aged in cool cellars, give that single malt a unique distinctive flavour...a taste that makes

one willing to pay the extra cost (Glenfiddich)..so it must be with aged NOS PIOs...some mystiques best be

left for future generation guitarists to look forward to.

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