Resistance, inductance, etc. do not come in to play when you use a capacitor for a tone control. Those specs matter for other applications, where you have more current, voltage, etc.
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OIL AND PAPER CAPACITOR
- Thread starter shababy32
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- mods oil paper precision bass
Resistance, inductance, etc. do not come in to play when you use a capacitor for a tone control. Those specs matter for other applications, where you have more current, voltage, etc.
Pbassmanca
In the pocket n' thumpy. So woody, so greasy...
Sitting in Emergency room with sliced open heel, saw this post and laughed out loud!
..........like an idiot!............
It's handy to have a meter that measures capacitance. That way you know what you're putting in the bass.
Instead of buying a $20 cap, install a pin socket connector so you can switch out caps without soldering, and buy a bunch of caps with different values.
Ceramic capacitors in the range used in basses are typically an x7r dielectric. When you solder them, the heat "sets" them to an initial value. Over time, they lose capacity - a few percent the first month, a few percent the next year, another few percent the next decade. The caps in a 60 year old Fender still work, but they work a little different than the day they were installed.
X7r's have some other non- ideal behaviors, but they're not too significant in a bass guitar.
If you want caps that don't change over time, I suggest poly film caps. Yes, they're about 10 times the price - 50 cents instead of 5.
X7r's have some other non- ideal behaviors, but they're not too significant in a bass guitar.
If you want caps that don't change over time, I suggest poly film caps. Yes, they're about 10 times the price - 50 cents instead of 5.
Thank you, that's what I thought. This means I need never be concerned about the quality of the tone cap in my bass. Ever.
If you truly understand the physics of the caps ...then there are differences that can measured..
The ESR of the old paper oil caps is absurdly high in ohm range in some cases..... Ceramic X7R's are in the 10 to 30 mOhm range..
When dealing with pickups you have inductance and leakage inductance that creates a resonance with respect to the capacitance in the filter circuit...2nd order..
The high ESR will tame the Q and lower these resonant peaks...that's what some people are hearing...it can be measured on a network analyzer and it IS in the audio spectrum..
You can even step pulse the equivalent circuit with X7R caps and watch the ringing in a guitar pickup circuit..... Music is all about the transients..especially at the pick-up level... not much steady state signal going on in this neck of the woods..
The ESR of the old paper oil caps is absurdly high in ohm range in some cases..... Ceramic X7R's are in the 10 to 30 mOhm range..
When dealing with pickups you have inductance and leakage inductance that creates a resonance with respect to the capacitance in the filter circuit...2nd order..
The high ESR will tame the Q and lower these resonant peaks...that's what some people are hearing...it can be measured on a network analyzer and it IS in the audio spectrum..
You can even step pulse the equivalent circuit with X7R caps and watch the ringing in a guitar pickup circuit..... Music is all about the transients..especially at the pick-up level... not much steady state signal going on in this neck of the woods..
If you play with your tone control all the way up, there's no point at all.
Even if you don't, electronically they're the same, unless one has fallen out of spec. It's guitarist voodoo snake oil.
Even if you don't, electronically they're the same, unless one has fallen out of spec. It's guitarist voodoo snake oil.
A new capacitor has an ESR (equivalent series resistance) of fractions of an ohm. PIO capacitors are supposed to have higher ESR when new than other types, but it's still in the few ohm range. The capacitor goes in series with a 250Kohm tone pot. A few ohms of extra series resistance is negligible.
Really old capacitors might be leaky and weird but even so I doubt their ESR is comparable to the 250K tone pot, and it's not clear that leaky and weird is desirable in a tone control.
Really old capacitors might be leaky and weird but even so I doubt their ESR is comparable to the 250K tone pot, and it's not clear that leaky and weird is desirable in a tone control.
I'm not sure that tone controls are even desirable themselves.
I just use the same thing I use in most of my pedals...5% tolerance polypropylene film, usually Topmay or old Xicon "Greenies." I don't believe in different parts having different "tone" in a passive circuit, and probably never will.
Save the money on that mojo part and just buy a decent set of pots and a quality output jack.
Save the money on that mojo part and just buy a decent set of pots and a quality output jack.
<off topic>
I have driven the length (N to S) of the state of Mississippi twice in the past year - and both time was very nearly washed off of the road by rain the likes of which I have only seen in the tropics.
Seems to me that the cosmos is dropping a hint on y'alls (or at least me!)
I have driven the length (N to S) of the state of Mississippi twice in the past year - and both time was very nearly washed off of the road by rain the likes of which I have only seen in the tropics.
Seems to me that the cosmos is dropping a hint on y'alls (or at least me!)
The other parameters of capacitors can come into effect in some applications as line6man said. My day job is designing radio equipment and at many MHz to a few GHz the inductance of capacitors can play a significant role in how they perform although the tiny chip caps we use have so little inductance that it can be ignored in many cases. It would take 1.3 mH of inductance to make a 47nF capacitor self resonant at 20kHz and a lot more at bass frequencies. No capacitor you can buy has that much inductance so you can safely ignore the inductance of your tone cap!
The series resistance of capacitors can play a big role in the losses in a radio frequency circuit and it can wreak havoc with your efforts to stabilize a switching power supply. The only effect of the series resistance in a bass guitar tone cap is to set a lower limit on the range of the tone control pot. With modern caps the series resistance is inconsequential. If you want to argue that it is significant with PIO caps, well, I'm not going to bother to argue that matter. However if you find that the series resistance of PIO caps is the key to your musical performance you can simply add a small resistor in series with your ceramic or film tone cap and get exactly the same result for less money....
The common 47nF tone cap (aka, 0.047uF) has an impedance of 113kOhms at 30Hz. So it is not entirely out of the circuit when your 250k tone control is dimed (turned all the way up for those unfamiliar with the term dimed). If you can hear the difference between 250k and 500k and no-load tone pots then you should be able to hear the difference between a 47nF tone cap and a piece of wire. However the difference is subtle even for young ears with excellent high frequency response and I doubt that anyone can hear the difference between a 5% cap and a 20% cap with the tone control dimed.
The series resistance of capacitors can play a big role in the losses in a radio frequency circuit and it can wreak havoc with your efforts to stabilize a switching power supply. The only effect of the series resistance in a bass guitar tone cap is to set a lower limit on the range of the tone control pot. With modern caps the series resistance is inconsequential. If you want to argue that it is significant with PIO caps, well, I'm not going to bother to argue that matter. However if you find that the series resistance of PIO caps is the key to your musical performance you can simply add a small resistor in series with your ceramic or film tone cap and get exactly the same result for less money....
The common 47nF tone cap (aka, 0.047uF) has an impedance of 113kOhms at 30Hz. So it is not entirely out of the circuit when your 250k tone control is dimed (turned all the way up for those unfamiliar with the term dimed). If you can hear the difference between 250k and 500k and no-load tone pots then you should be able to hear the difference between a 47nF tone cap and a piece of wire. However the difference is subtle even for young ears with excellent high frequency response and I doubt that anyone can hear the difference between a 5% cap and a 20% cap with the tone control dimed.
Les Paul players, or at least those bored and opinionated enough to join dedicated Les Paul forums, claim to be able to hear the difference. They get upset, or shall we say triggered, by anybody that suggests that capacitor construction type has no impact on tone for capacitors of the same value. Naturally the obscure long-extinct capacitors on the 1950s have a better tone than the shriller, harsher and colder sounding modern capacitors. If nothing else, a modern ceramic capacitor costs cents, retail, whereas those old capacitors are four times the size, have weird lines painted on them and cost anywhere from $20 to $100 each. They have to be better, and straight-talking no-messin' guys (who just happen to own companies with cheesy hillbilly names like 'Rebel Guitar Coalition', who just happen to sell aftermarket components and wiring harnesses for Gibson guitars) also happen to agree. The fact that these Les Paul guys can claim to hear the difference through 30 feet of coily guitar cable, 100 watts of boutique Marshall clone with idiosyncratic and highly characterised tone, a boutique Tubescreamer clone, and the nasty stock buffer in a Crybaby really beggars belief. Especially given that most of them must be pretty deaf given 1) their general age and 2) the number of Nugent concerts they happily attended back in the day.
Don't fall for the hype. I'm being totally harsh here, and I don't mean the OP in any way as he's asked an innocent question, but if you think $50 of capacitor is getting between you and better musicianship then you might need to wake up. Bassists seem to be generally smarter at 1) accepting innovation where a concrete argument exists in its favour and 2) weeding out the sort of faddy elitist cork-sniffing nonsense that some corners of the guitar universe take a perverse pride in adopting and endorsing.
Don't fall for the hype. I'm being totally harsh here, and I don't mean the OP in any way as he's asked an innocent question, but if you think $50 of capacitor is getting between you and better musicianship then you might need to wake up. Bassists seem to be generally smarter at 1) accepting innovation where a concrete argument exists in its favour and 2) weeding out the sort of faddy elitist cork-sniffing nonsense that some corners of the guitar universe take a perverse pride in adopting and endorsing.
I have in my guitars and bass this adds lot of mojo
You can drive your car with emergency wheel or the sport wheel this is the same.
If you can pay use it very good caps.
whatever you're happy with... but physics will not change because of that
People feel that if they spend more, then they might get better too. There are always people will exploit that part of the market.
This could be a topic for a whole 'nother thread (or a poll): "Do you ever set the tone control(s) on your bass to anything other than '10'"? I have, maybe once or twice, in a really unusual situation.
