Is it essential to have a capacitor in my basses?

[StevieD_FenderP2009]

Hey guys
I have a Custom P Bass and an Epiphone Embassy Bass which I have wired both up without a capacitor in.
After reading through a few things on here it seems that alot of people put down part of their tone to whichever capacitor is installed in the bass.

So, which capacitor would you recommend to go with a Precision bass loaded with 250k Volume + Tone and Spunky Dunkys SPB-3's (going to be upgraded to SPB-1's to match the Steve Harris signature) but to give it a really clean and thumping high end?

Oh, also, where does the capacitor have to be wired in to?
Apologies for being so stupid

Cheers guys
Stevie

[Ou7shined]

Just quickly nicked off t'interweb, but the basics are there.....

[b]How they work:[/b]

The capacitor which is connected to the tone pots in your guitar (or between volume and tone in the case of active pickups) can have quite an impact on the sound produced by your guitar. The purpose of the capacitor is to decrease the treble frequencies as you roll down the treble knob on your guitar. In short a higher value capacitor will bleed off more treble as you turn down the tone, and a low value capacitor will not bleed off as much.

The downside to bleeding off too much treble is that it can result in a muddy and bassy output, and the opposite can be true if you are using a capacitor value which is too small, leading to a very bright and trebley sound. In slightly more complex terms the tone pot and capacitor work together as a low pass filter, as the tone pot is turned down more of the treble frequencies are sent to ground, and the lower frequencies are sent to the output.

[b]What should I use then?[/b]

Generally manufacturers which fit there guitars with humbuckers will use lower valued capacitors as the pickups generally have a 'darker' sound, this is partly due to the pickup and also due to the many of the guitars which have humbuckers i.e. Gibson Les Paul. Therefore most passive humbuckers are wired up with 0.022uF capacitors. Whereas guitars using single coils such as many Fenders will use a larger capacitor value, such as 0.047uF. Single coils have a tendancy to be brighter sounding and produce a more twangy sound, therefore more of the treble is cut with the use of the tone knob.

However this is not a rule! You can use pretty much whatever size capacitor within reason. For passive pickups any value between 0.01uF and 0.1uF would be acceptable. The best idea is to buy several different values and try them out in your guitar to find out which produces the sound that you prefer. The most common values are 0.022uF and 0.047uF for passive pickups and 0.1uF for active pickups.

[b]Finding out the value of a capacitor:[/b]

Capacitors use a code on the side which tells you the value of the capacitor and also its tolerance. It is written as a 3 digit code, the first 2 digits tell you the value of the capacitor, and the 3rd digit tells you the multiplier. The letter on the end signifies the tolerance of the capacitor (i.e how accurate its actual value is to the stated value). For example the picture below shows a capacitor in my SG which says 473K on the side. This gives the value in pF (picofarads) This means its 47 x 103 = 47000pF = 0.047uF. The K is the acceptable tolerance which for this capacitor is +/- 10%.



[b]Multiplier and Tolerance Calculations:[/b]

To calculate the value of your capacitor take the first 2 digits of the code and multiply it by 10 to the power of the 3rd digit (Essentially adding the (3rd digit) number of zero's onto the end of the first 2 digits). This gives you the value in Picofarads (pF), the capacitors used in guitars are generally given in microfarads. To convert from picofarads to microfarads just multiply the number by 10 to the power of -6 (10-6)

10-3 = mF (Millifarad)

10-6 = uF (Microfarad)

10-9 = nF (Nanofarad)

10-12 = pF (Picofarad)

[Mr. Foxen]

No capacitor is better for high end. Lot of balls is said about capacitors, the value of it is about the only thing that matters, it's actual value, not its marked one, some have very wide tolerances.

[StevieD_FenderP2009]

I must be really stupid because alot of that made absolutely no sense to me

The wiring kit I bought was the same wiring kit as used in Fender's current AM series and the Steve Harris sig series but I just didn't bother wiring in the cap and I think it was a 0.05 cap... now I don't know what that means but yeah, i didn't wire it in

From what else I read here, it looks like capacitors aren't actually needed then?

[LawrenceH]

[quote name='StevieD_FenderP2009' post='976023' date='Oct 3 2010, 02:49 PM']I must be really stupid because alot of that made absolutely no sense to me

The wiring kit I bought was the same wiring kit as used in Fender's current AM series and the Steve Harris sig series but I just didn't bother wiring in the cap and I think it was a 0.05 cap... now I don't know what that means but yeah, i didn't wire it in

From what else I read here, it looks like capacitors aren't actually needed then?[/quote]

They're not needed unless you want the ability to roll off the high end.

--However, counter-intuitively, in passive basses caps can make the overall tone a bit more bark-y because as you roll them off you get a slight peak just below the roll-off frequency. With my Jazz, if I roll the tone nearly but not quite off with the bridge pickup solo-ed, the mid-range stands out a little bit more. But the effect is quite subtle and doesn't sound like what you're after--

Edited October 3, 2010 by LawrenceH

[BOD2]

The capacitor is used as part of the tone control circuit. If you don't have a capacitor then the tone control on the bass won't work.

If you never actually use the tone control (and never intend to) then you could do away with both the tone pot itself and tje capacitor, and just have a volume control.

If you want to have a tone control then you need a capacitor and the standard Fender values are as good a starting place as any.

This link will show you where the capacitor fits in a standard P-Bass -

[url="http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=std_pbass"]http://www.seymourduncan.com/support/wirin...matic=std_pbass[/url]

[LawrenceH]

Here is a good graph from Audere which shows how the resonant peak on a passive bass pickup shifts downwards as you add capacitance.

[url="http://www.audereaudio.com/TechDetails.htm#capacitance"]http://www.audereaudio.com/TechDetails.htm#capacitance[/url]

Bear in mind that though the overall response of the pickup gets lower, shifting the peak from a region where the bass doesn't output much to one where it does, and/or from a region which the speakers can't reproduce well (say 4.5k through a 'typical' 12") downwards (say to 2.5k), will have the effect of apparently boosting high-end output.

Edited October 3, 2010 by LawrenceH

[tino]

[quote name='StevieD_FenderP2009' post='976023' date='Oct 3 2010, 02:49 PM']I must be really stupid because alot of that made absolutely no sense to me

The wiring kit I bought was the same wiring kit as used in Fender's current AM series and the Steve Harris sig series but I just didn't bother wiring in the cap and I think it was a 0.05 cap... now I don't know what that means but yeah, i didn't wire it in

From what else I read here, it looks like capacitors aren't actually needed then?[/quote]
CORRECTOMUNDO

[GarethFlatlands]

I'm rewiring an old bass with 250k pots, Fender schematics recommed a 0.05uf cap.

As to why, I'm not smart enough to know but the above advice all looks solid.

[Bobby K]

[quote name='LawrenceH' post='976031' date='Oct 3 2010, 02:54 PM']They're not needed unless you want the ability to roll off the high end.[/quote]

So, without a cap in at all, you're theoretically supposed to get the same sound you would with a cap in and tone pot on 10?

Or am I stoopid...??

[Mr. Foxen]

[quote name='Bobby K' post='976169' date='Oct 3 2010, 05:14 PM']So, without a cap in at all, you're theoretically supposed to get the same sound you would with a cap in and tone pot on 10?

Or am I stoopid...?? [/quote]

In theory right, but there'll probably be some effect from the cap anyway.

[flyfisher]

The thread title is a good question and, given the range of tone controls available on most bass amps these days, I sometimes wonder myself.

Seems to me that the very primitive tone control on most basses is just a historical throwback to the early days when bass amps provided less flexible tone shaping.

So the answer to the original question must be no, it's not essential.

Indeed, in that seemingly never-ending seach for the 'perfect tone', a simple RC filter starts to look pathetically puny when faced with multi-band tone control on the bass amp plus a multi-band graphic equaliser pedal or even a full-on DSP-powered amp-modelling wonderbox.

[Delberthot]

I've tried removing the cap and even going to the extent of removing the pots and going straight to the output jack.

Wiring straight to the output has a huge influence on tone. it sounds nothing like having volume and tone all the way up. Simply being there despite not using it has an effect.

As for capacitors. go with what others have said and try loads, they're not expensive.

Just like after searching for years for plectrums I finally find 'the ones', coincidentally its the same ones that Chris Squire uses, I found the capacitors I needed to help me get the sound in my head - 0.1 paper in oil caps, same spec as what Leo Fender used in the first Precisions before changing them for cheaper alternatives

[Truckstop]

Delberthot, the drummer in your avatar looks like he's at the wrong gig.

Truckstop

[StevieD_FenderP2009]

Hi guys

thanks so much for the feedback and different responses. I may be just echoing what I said earlier but there really is alot of mixed responses on here about the caps, some people saying they're good and some people saying they're not needed.

I think i'll definately go down the test and trial route and see if there's one that boosts my tone at all or makes any needed difference to my bass.
Other thing is, with the epiphone that I mentioned in my first post, I've got no volume or tone pots but instead now just had a single DPDT switch between the hot wire of the pickup and the output jack. I also have the bridge ground wire running to the switch but the bass is still really noisy, makes alot of buzzing when the switch is turned to on (but obviously nothing when it's off) so does anyone know any way of getting rid of this buzzing and humming?

Cheers guys!

[Mr. Foxen]

Is the bridge connected to the earth? Check the earth path is still complete with the switch on.

[krispn]

Hey there

It's important to remember that the tone control on any bass is effectively a roll off control. Its like turning a tap at your sink - when your tone control is turned all the way up your signal is going straight out of the bass to your amp and 'not' affecting the tone just like if your tap was turned on. However the tap itself naturally has an effect on the flow of the water due to it's size, its diameter and just simply by virtue of it being there.

If you didn't have the tap connected you might get a different flow of water, maybe a fast uncontrolled stream or jet of water and certainly one you had no control over. Likewise with cap's - without one you could expect a tone that was 'hot', and uncontrollable in the sense that it wasn't connected to a control knob.

Remember just by having cap's in your circuit they will have an effect to your tone. Therefore its natural to think that the size of the cap then determines how much tone gets through to your amp although when you tone knob is wide open you 'shouldn't' hear any difference to your tone.

If your after the Steve Harris tone I'm sure there is much info and spec sheets outlining his wiring preference, caps used etc.

If its any consolation.....

I just recently changed the cap in my USA P Bass to a paper in oil cap, a 0.1uF and for my needs its a really great cap. It just sounds good to my ears - I normally use it to tame a little top end off my round wound strings. Someone mentioned that the tone know is a throwback to a bygone age now that amps, pedals and multi FX are so complex and that is a valid point. However for me and my style I can get the tonal variety right at my fingertips with a little tweak of the tone control. I enjoy the feel and tone of flatwounds but they don't always suit the songs I play in the band. The tone control and the 0.1uF allows me to get the nice bassy tone I like plus with the twist of the control can give more definition with the tone wide open.

I have a spare paper in oil cap (its a brute) but should fit into your control cavity if you want to try it out?

Hit me with a PM and I'll send it to ya if you like.

Edited October 4, 2010 by krispn

[EdwardHimself]

[quote name='Ou7shined' post='975987' date='Oct 3 2010, 02:13 PM']This means its 47 x 103 = 47000pF[/quote]

10^3 surely?

[StevieD_FenderP2009]

Krispn - PM'd, Cheers alot bud

Mr. Foxen - Yeah, the earth wire is running from the bridge to the top pin of the DPDT switch but it still creates this awwwwffful buzzing noise

[Mr. Foxen]

Also note Steve Harris removes the tone control from his bass, a habit from playing small gigs where people would touch the knobs, he signals a guy for tone changes.

As for buzzing, I'd get a meter and check everything is earthed to everything else.

[EdwardHimself]

[quote name='Mr. Foxen' post='977927' date='Oct 5 2010, 02:38 AM']Also note Steve Harris removes the tone control from his bass, a habit from playing small gigs where people would touch the knobs, he signals a guy for tone changes.

As for buzzing, I'd get a meter and check everything is earthed to everything else.[/quote]

That's what i'd probably do. In fact that's what i did do i don't bother with tone controls, just don't see the need really.

[StevieD_FenderP2009]

Ahhh cheers for the tip there.
Does anybody know how to wire up a P Bass with just a volume control then?
Can't seem to find the right diagram on the net (but I'm tired so i'm probably not looking properly)
Cheers
Stevie

[BigRedX]

Just take the standard P-Bass wiring diagram and leave out the tone pot and the capacitor.

[StevieD_FenderP2009]

Some news on the wiring

Epiphone: Fully wired and working perfectly. Now all I need to do is get some new tuning pegs (one snapped and another one just chewed all the teeth off) and then give it a set up ready for gigging. It actually sounds alright as well which was a massive suprise to me tbh. Encore pickups with some dead Fender strings on it (only the A and D string on the E and A tuners to test it) and it sounds quite punchy with alot of bottom end. Also, suprisingly, there isn't ANY humming what so ever now. I ran an earth wire from the side of the DPDT switch to the hot wire from the pickup and it's stopped all humming

P Bass Custom: Removed the tone pot, cleaned it, re-wired it, put it back together and there's a slight buzzing issue which is beginning to annoy me. I plugged it into my Line 6 Toneport UX2 and brought up the input monitor on my laptop screen to see what came up. When the bass is on full volume without anything being touched on it, it reads -45dB (at -60dB it means there is no input at all) but when you put your hand on the strings, it reads -52dB and there is still the buzzing noise. I have it wired exactly how the Squier (dare I say it) Pete Wentz (oh I did say it...) P Bass wiring diagram shows (I remembered that his signature P only has the 1 volume control and no tone, and may I add, I hate Fall Out Boy...) but yeah, still the buzzing so is there any way to stop this or will I just have to live with it?

Cheers

[Mr. Foxen]

Not unlikely it is picking up hum from your laptop, lots of complicated electrickery going on there. I use a CRT monitor or TV to check for hum.