capacitors?
- Thread starter timski28
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Capacitors pass AC signal and block DC.
In the guitar the pickups put out an AC signal.
The bigger value of the capacitor, the easier it is to pass AC - so lower and lower frequencies are passed (lower freq=closer to DC)
The capacitor is connected to the same terminal as the pickup "hot".... and to a potentiometer which regulates how easy it is for the passed signal to reach ground.
By varying the potentiometer, you present a range from almost no ohms resistance to about 250k or 500k ohms of resistance. This range allows a decent control over how much "highs" are shorted to ground, giving the effect of a treble control.
In the guitar the pickups put out an AC signal.
The bigger value of the capacitor, the easier it is to pass AC - so lower and lower frequencies are passed (lower freq=closer to DC)
The capacitor is connected to the same terminal as the pickup "hot".... and to a potentiometer which regulates how easy it is for the passed signal to reach ground.
By varying the potentiometer, you present a range from almost no ohms resistance to about 250k or 500k ohms of resistance. This range allows a decent control over how much "highs" are shorted to ground, giving the effect of a treble control.
Basically a capacitor turns a volume control into a tone control. You wire it to a potentiometer and it rolls off treble instead of volume. Check out some wiring diagrams. Seymour Duncan have some good ones in the support section of their website. There are different value capacitors for different applications. Have fun, and welcome to the board :icon_thumright:
To clarify a little, in case it's still a bit confusing: Potentiometers redirect 'hot' signal to the ground. ie, your volume control redirects the signal from the hot output (ie sound) to the ground (ie no sound). If you stick a capacitor along the way, it'll block all but the high frequencies (ie the high frequencies go to ground, but the rest stays). Higher capacitor values allow lower frequencies through, the traditional values being .047 for Fender products and .023 for Gibsons. Other values could be and sometimes are used ie 1 meg which allows lower and lower frequencies to be removed from your 'hot' sound. Finally, you don't need to have a pot (tone control) at all; some have used a 'sweet switch' that just turned on or off a capacitor. I saw a chart which showed a non-linear relationship between cap value and amount of rolloff, in other words there wasn't much difference between .047 and .023. Good luck!
+1 on the seymour duncan website, it's really good for pickups and electronics.
+1 on the seymour duncan website, it's really good for pickups and electronics.
Yeah you could do all of the things mentioned - none, switches, control from the pup switch, whatever. Loads of guitarists never ever use their tone controls, so some guitars don't bother with it. Simplicity can be a goal in itself. The term sweet switch, I believe, comes from PRS but the idea is just simple, basically instead of having a tone pot you have a tone switch - so it's like having the option of '0' or '10' but no in between. I believe the Jazzmaster had a bunch of these too, didn't it?
One reason for these multiple options, I believe, is that fact that every component in your circuit adds to the 'load', or drag, whatever - added resistance. So in theory, a guitar with no controls whatsoever (just a pickup and a wire to the output jack) will be louder and brighter than one with all its controls turned to 10. I personally have no idea to what extent people can actually hear that difference, though. Another reason is that keeping the controls simple means it's more likely that you'll use them, and easier to use them in the middle of a song.
I drew this diagram to illustrate the switch concept. But the basic idea of any of the options is, provide a cap with a path to ground and some way to select it on or off. Good luck!
One reason for these multiple options, I believe, is that fact that every component in your circuit adds to the 'load', or drag, whatever - added resistance. So in theory, a guitar with no controls whatsoever (just a pickup and a wire to the output jack) will be louder and brighter than one with all its controls turned to 10. I personally have no idea to what extent people can actually hear that difference, though. Another reason is that keeping the controls simple means it's more likely that you'll use them, and easier to use them in the middle of a song.
I drew this diagram to illustrate the switch concept. But the basic idea of any of the options is, provide a cap with a path to ground and some way to select it on or off. Good luck!
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DiMitriR33
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Jwheeler said:
i haven't done this yet but i plan to. i beleive the gibson lucille has one. as well as the standard gibson controns. i know a guy who has a lucille and he always sounds amazing.
N
neilium
Guest
Actually, that's a varitone on Lucille. One inductor and 6 different RC networks to give you 6 different notch filters:
http://www.blueshawk.info/official_gibson_schematic.htm
Position 1--> no cut
Position 2--> -5db at 1950hz
Position 3--> -12db at 1 100hz
Position 4--> -16db at 620hz
Position 5--> -18.5db at 360hz
Position 6--> -21db at 1 20hz
http://www.blueshawk.info/official_gibson_schematic.htm
Position 1--> no cut
Position 2--> -5db at 1950hz
Position 3--> -12db at 1 100hz
Position 4--> -16db at 620hz
Position 5--> -18.5db at 360hz
Position 6--> -21db at 1 20hz
Actually,
The Blueshawk, and Lucille, and other VariTone guitars have one (or two) inductors, and five (or ten) capacitors to make 5 LC tanks, plus no effect, for six settings.
If you look at how they're in the circuit, its easy to see that the sole reason for the 10m resistors is to keep the caps "charged", which makes them not "pop" after periods of disuse.
The 100k resistor is a load balancing resistor. What it does is makes sure you've got some load to counter the load of the LC tank. If it weren't there, the effect would be greatly diminished. Why? Because the LC circuit is a higher impedance than the pickup and the natural order of things would just have the electrons not go there. By putting in the resistor, it guarantees that the signal will detour throu the LC tank(s).
The value of the load balancing resistor will vary, according to the impedance of the L in the LC circuit... and to a lesser degree the ESR of the C. L=coil, C=capacitor
The excellent humbucking inductors from Lawrence are so low an impedance, that you don't need any load balancing resistor at all - or in fact - a sort of reverse load balancing resistor in most guitars. Whereas the Gibson inductor well beyond the impedance of most pickups, the Lawrence one is a mere 55ohms impedance. Transparent!~
By varying the inductance of the coil - the degree of high frequency retention is altered. Lower inductance preserves very high frequencies, while raising the inductance preserves more lower frequencies. Something in about 2hy will just start to get into the 2nd harmoncs. Going into 4hy will give upper fundamental frequencies - all dependent on the pickups of course. The capacitor preserves more and more lows. Bigger caps = more lows, smaller fewer lows. So, what Gibson has done is more or less got a variable low cut filter going on. It works well.
The Blueshawk, and Lucille, and other VariTone guitars have one (or two) inductors, and five (or ten) capacitors to make 5 LC tanks, plus no effect, for six settings.
If you look at how they're in the circuit, its easy to see that the sole reason for the 10m resistors is to keep the caps "charged", which makes them not "pop" after periods of disuse.
The 100k resistor is a load balancing resistor. What it does is makes sure you've got some load to counter the load of the LC tank. If it weren't there, the effect would be greatly diminished. Why? Because the LC circuit is a higher impedance than the pickup and the natural order of things would just have the electrons not go there. By putting in the resistor, it guarantees that the signal will detour throu the LC tank(s).
The value of the load balancing resistor will vary, according to the impedance of the L in the LC circuit... and to a lesser degree the ESR of the C. L=coil, C=capacitor
The excellent humbucking inductors from Lawrence are so low an impedance, that you don't need any load balancing resistor at all - or in fact - a sort of reverse load balancing resistor in most guitars. Whereas the Gibson inductor well beyond the impedance of most pickups, the Lawrence one is a mere 55ohms impedance. Transparent!~
By varying the inductance of the coil - the degree of high frequency retention is altered. Lower inductance preserves very high frequencies, while raising the inductance preserves more lower frequencies. Something in about 2hy will just start to get into the 2nd harmoncs. Going into 4hy will give upper fundamental frequencies - all dependent on the pickups of course. The capacitor preserves more and more lows. Bigger caps = more lows, smaller fewer lows. So, what Gibson has done is more or less got a variable low cut filter going on. It works well.
N
neilium
Guest
True, my misread. Only five LC combinations. But, inductor and cap in series to ground, isn't that a notch filter?
DiMitriR33
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i guess i mis understood the varitone. i'd seen a similar looking product in an article about p/u's that was just caps. got them confused.
i beleive you are correct.
neilium said:
i beleive you are correct.
O
OzziePete
Guest
tfarny said:
The Jazzmaster has an alternate volume and tone pot that you could pre set, and switch to at the flick of a switch.
The Jaguar has a 3 switch control plate, which might be what you are referring to. The Jag's control plate has on/off switches for the pickups, and an extra switch that brings in an extra capacitor. Fondly referred to by Jag buffs as a 'strangle' switch, due to the resulting tone it gives.
Gretsch guitars, however, had a toggle switch that had two different pre set tone cap values mounted either side of the switch, and no tone pot. All or nothing.
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