Vol / Tone pot / Cap variations

[fleabag]

What have you tried on dual humbuckers basses with Vol Vol Tone setup ?

I need some feedback on the results of different layouts on V V T wiring

500k vol 500k vol 500k tone with which value cap

250k vol 250k vol 250k tone with which value cap

500k vol 500k vol 250k tone with which value cap

500k vol 250k vol 250k tone with which value cap

250k vol 500k vol 500k tone with which value cap

250k vol 250k vol 500k tone with which value cap

I think i've covered the permutations

Just looking at options, and i guess some will be horrible ..

[KiOgon]

You need to get out more

[fleabag]

I see you've put some real thought and not enough emotes in your post

[Grangur]

For the punchy sound you're looking for I'd suggest 500, 500, 250.
500 on the volume gives more clank. The value of the resistance on the tone pot doesn't change the tone. What a high resistance tone pot will do is give you 50% of the rotation won't do much.

On the value of the capacitor; I once worked on a bass and connected 2 capacitors with a switch. The values were significantly different, but the tone difference between them was minimal.

[fleabag]

THanks Gran - much more helpful

I was def thinking of 500 for the Vols, but undecided on the Tone. I doubt anyone would suggest 250's for the vols, but wanted to see if anyone had, and if so, what tone pot they'd have used.

I have enough pots here to experiment, but am lacking in caps. Only got 0.047's

[MoonBassAlpha]

You can put 2 caps in series to halve the value or in parallel to double. That's probably the range of values most people will muck about with anyhow...

[fleabag]

Thanks MBA

Is it true that if you play with your vols ( or is it tone ) on max, the cap has no affect , or very little until you back off slightly ?

[Chienmortbb]

[quote name='Grangur' timestamp='1453755731' post='2962534']
For the punchy sound you're looking for I'd suggest 500, 500, 250.
500 on the volume gives more clank. The value of the resistance on the tone pot doesn't change the tone. What a high resistance tone pot will do is give you 50% of the rotation won't do much.

On the value of the capacitor; I once worked on a bass and connected 2 capacitors with a switch. The values were significantly different, but the tone difference between them was minimal.
[/quote]The passive circuits are a variable low pass filter and if you change anything in it, you will change the tone.

[Grangur]

[quote name='fleabag' timestamp='1453762648' post='2962633']
Thanks MBA

Is it true that if you play with your vols ( or is it tone ) on max, the cap has no affect , or very little until you back off slightly ?
[/quote]

In theory, if you turn the tone pot to the point that it's on its lowest resistance, the pot will be short-circuiting the cap. So in theory at this point the capacitor has little effect. You can't say it will have no effect, but it will be greatly reduced.

[iiipopes]

The capacitor determines, in conjunction with the pickup coil, what the hinge or rolloff frequency will be. Generally, the higher the value of the cap, the lower the rolloff frequency, and vice versa.

The volume potentiometer, since the third leg is usually grounded, determines the loading to ground, which can affect the resonant peak of the circuit. Generally, the higher the value of the potentiometer, the higher in frequency and amplitude of the resonant peak frequency of the pickup. But this is usually only subtly audible at best, especially on a bass.

Because a typical tone cap circuit brings the capacitor off the wiper lug and grounds without the use of the 3rd lug, using a 500 kohm pot turned down to 250 kohms (with an audio or log taper pot, that means turning the knob down from 10 to about 7 or 8), has an identical effect on the circuit.as using a 250 kohm pot. The difference is only which number on the knob, or degree of rotation of the pot shaft, gives the same tone. Using the 500 kohm tone pot will decrease loading to ground when dimed, and may result in the bass being subtly brighter.

I don't think anybody has run frequency analyzer traces on the same instrument with the same pickup but with the different value pots and caps, although a few have run them on just the caps.

Since historically dual coil humbuckers have greater inductance than single coil pickups, and/or more intra-coil capacitance as well, it has been traditional to use 500kohm pots in order to raise the resonant frequency as high as possible to get more presence when desired out of a humbucking pickup. The main exception to this is the traditional split Precision pickup - the factory continues to use 250 kohm pots as standard for this pickup.

The point being is that you would probably use the same value capacitor irrespective of the volume and tone pots used. Standard is .047 microfarads. .033 will keep more mids in the mix as it is rolled off. .022 is for those who want guitar-like brightness. .068 will be darker, and the darkest commonly used for dub tone, and which was the original value used in the '51 - '56 P-basses, is .1, giving huge thump when rolled off completely.

With the tone pot dimed out, the 500 kohm volume pot will give the pickup the slightest bit more presence, but that goes away as soon as you start rolling off the tone knob.

So after all is said and done, most folks still come back to the traditional 250 kohm audio taper pots and .047 capacitor for a conventional bass pickup circuit. I do like a little more mids when rolled off, so like the original J-bass stack knob bridge pickup circuit, I use a .033 for my tone control cap.

Hope this helps.

Edited January 26, 2016 by iiipopes

[fleabag]

Thanks all - info & advice appreciated

Going with 500k/500k/250k/ 0.047uF or 33

Edited January 26, 2016 by fleabag