Volume/volume pots

[Joebuscus217]

I want to wire a new project bass. The pickguard I got only has two holes in it for pots or output or whatever. I'm putting the output jack on the side to that's no problem, but I want to put a Killswitch on the first hole, leaving just one hole to have pots to control a pj configuration. Could I wire concentric pots to control volume/ volume, and if so, how, and what do I need to know to do it. Btw I don't care about a tone pot because I never use it

[DeepEnd]

A concentric pot is just two pots together. You can wire it any way you want. Figure out which one you want to control the P pickup and which you want to control the J pickup. Here's an interesting example with a Master Volume and a second Volume for the Bridge (J in this case) pickup:

 

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[Joebuscus217]

What about like capacitors. In complete honesty, I have no idea what they're used for but don't you need them?

[isaac42]

What about like capacitors. In complete honesty' date=' I have no idea what they're used for but don't you need them?[/quote']

 

Not for volume controls.

[DeepEnd]

What about like capacitors. In complete honesty' date=' I have no idea what they're used for but don't you need them?[/quote']

As isaac42 said, no. A tone control cuts the highs; that's when/why you need a capacitor. For a straight volume control all you need is a pot.

[WRGKMC]

A kill switch as you will likely find is a waste, especially on a bass where its unlikely to be used as an effect. even on a guitar you can do the EVH plan crash imitation and quickly find out its wasting a control spot there too.

 

On a bass where the notes are normally clean all you have to do is stop strings as most finger players do and the string silences. You don't need an onboard kill switch for that.

 

If you're need to simply silence the pickups between songs your volume pots do that already.

 

If you have two sets of pickups you can put in a 3 way switch which is far more useful. If you use two volumes just leave one of the pots turned down and that three way becomes a kill switch.

 

If you go with a master volume then the second can be a tone control which is handy for removing brightness.

[isaac42]

There is one use I know of for a capacitor and a volume potentiometer. Some people find that, when they turn the volume down, they lose some high end. Putting a small cap between the hot lead and the wiper helps with that. When the volume is on full, the cap is shorted out by the potentiometer and has no effect, but as the volume is lowered, it creates a secondary path for the highs that doesn't go through the pot. Most of us don't feel the need for it.

[WRGKMC]

You can use caps to pass or block frequencies. A Typical tone control uses a low value capacitor to remove highs. Capacitors pass AC in varying amounts depending on the value. A .05 ~.01uf cap will pass the high frequencies to ground and (block them from getting to the amp) leave the lower frequencies alone.

 

As Issac mentioned you can also use a cap as a high pass filter by placing it over the pot. The cap is essentially put in series with the signal and parallel to the pot and instead of blocking the high frequencies it bypasses the pot allowing the high frequencies to pass unaffected by the pot thereby maintaining the highs as the rest of the frequencies are attenuated down. The pot acts as a balance between full frequencies and full highs.

 

Theres another way to use caps that doesn't seem to be known or used by musicians allot, though it has shown up in various guitars over the years. Rickenbacker, Dan Electro and a host of other unique guitars come to mind.

 

Like a treble bleed a cap can pass frequencies. Instead of using a weak cap to only pass highs, you can use a higher value cap to pass mids and some of the lows too, but not all the lows.

 

The cap when combined with a pot then becomes a bass control. It doesn't boost bass of course it simply attenuates it like a tone control attenuates the treble away.

 

Companies like Rickenbacker typically used a .047 cap on the bridge pickup to remove bass frequencies and make that pickup jangle compared to the neck pickup.

 

An example of how this can make a bass sound can be heard on any YES album. Billy Squire used a band pass cap on his Rickenbacker bass to remove lows and give the bass a tangy midrange tone which became an epic sound for that band.

 

Another example of it being used is for creating Eric Clapton's Woman tone. In that case the bass cut and treble cut are combined on a dual pot and when tweaked they remove highs and lows and leave the midrange.

 

Caps can be combined with a coil to produce a very narrow frequency too. The Varitone circuit was made popular by Gibson having a rotary switch and several cap/coil/resistors used to make selective band cuts and give the setting different tones. I've seen the circuit modified for bass and a variable push pull tone pot added to double the number of settings.

 

These are passive circuits however which can cause allot of gain loss. The question really boils down to how much on board control do you actually need and what is the point of having so much on board control when you can just as easily reach over and tweak an amps tone controls or use something like an EQ pedal for tones, or even add an active preamp/EQ on board.

[DeepEnd]

There is one use I know of for a capacitor and a volume potentiometer. Some people find that' date=' when they turn the volume down, they lose some high end. Putting a small cap between the hot lead and the wiper helps with that. When the volume is on full, the cap is shorted out by the potentiometer and has no effect, but as the volume is lowered, it creates a secondary path for the highs that doesn't go through the pot. Most of us don't feel the need for it.[/quote']

I thought about describing a treble bleed but I didn't want to muddy the waters with TMI. I prefer to answer the question that was asked. BTW, don't you need both a resistor and a capacitor for a treble bleed circuit?

[isaac42]

I'm pretty sure that Billy Squire never played for Yes.

[isaac42]

I thought about describing a treble bleed but I didn't want to muddy the waters with TMI. I prefer to answer the question that was asked. BTW, don't you need both a resistor and a capacitor for a treble bleed circuit?

 

Some people think so, so it's probably true, at least in some situations.

 

https://www.fender.com/articles/tech-talk/how-a-treble-bleed-circuit-can-affect-your-tone

[badpenguin]

Uhhh, you mean Chris Squire right?

[badpenguin]

You CAN use a resistor in a treble bleed, but I personally find it affects the taper of the volume control. So I don't use it, just a .001 cap wired between the in and the out of the pot.