Is treble roll-off the only possible type of passive tone control?

[Crowder]

I understand that a typical "Tone" knob on a guitar just sends some high frequencies to ground, eliminating them from the signal that passes down the cable. Easy enough.

Are other kinds of passive tone controls possible?

Would it be possible to have a tone control that sounded "normal" at its lowest setting, but gradually rolled off bass frequencies as it was increased? I think it might be useful for some applications.

 

[aussie_owner]

I understand that a typical "Tone" knob on a guitar just sends some high frequencies to ground, eliminating them from the signal that passes down the cable. Easy enough.

Are other kinds of passive tone controls possible?

Would it be possible to have a tone control that sounded "normal" at its lowest setting, but gradually rolled off bass frequencies as it was increased? I think it might be useful for some applications.

Reverend guitars have a Bass Contour knob that does exactly what you said. Very useful control for fine changing the response of a pickup.

 

[Astronaut FX]

I think you may be describing what Reverend calls contour and includes on all (?) of their guitars.

 

[JWDubois]

High pass, low pass, band pass, or band reject filters can all be achieved with passive components.

 

[Crowder]

High pass, low pass, band pass, or band reject filters can all be achieved with passive components.

Can any of these be achieved without unduly loading the pickups and changing their tone for the worse?

 

[stratter]

Most of them, yes.

 

[TheoDog]

G&L does a passive bass and treble control on their start styles (Legacy and S500) in place of the typical 2 tone knob config

 

[burningyen]

Reverend's BCC works beautifully.

 

[SouthpawGuy]

G&Ls PTB, Passive Treble and Bass controls, explained ...

 

[Jo-Jo Beans]

What sorts of components are we talking as far as passive high pass, band pass, and band reject? Would it be some variant of the Resistor/Capacitor circuit that a typical tone control uses? For example, how would you make a "moving" high pass filter where you could control the frequency? Just another potentiometer like tone?

 

[IPLAYLOUD]

Every Reverend Guitar except the Pete Anderson Tele has a BCC knob.
I gig with Revs all the time and use that knob often!

It takes their hot P90 to a Tele tone, their HB closer to a single coil...with no hum.

It also helps to "play' the room. I can add or subtract depending on what is needed.
(You can also run your amp right "on the edge" with the BCC down and turn it up to push it over the top. Works very nicely.)

 

[EADGBE]

Here's a passive tone circuit that reduces bass frequencies. I believe the cap is a .0047 μF.

 

[Jo-Jo Beans]

So (warning: electronics nerd-speak ahead) what's essentially happening here is two volume pots in a row. The first one is the "master volume" that rolls all frequencies down evenly. The second one has a treble bleed capacitor jumpered across its leads, and the .0047 μF value will always let a certain frequency and above through (in a treble bleed circuit, the capacitor always acts as a fixed high-pass filter). So when you roll down the second pot, you're still lowering the volume on all the frequencies, but the high frequencies bleed through the cap and get to the output. So sonically, it'll sound like you're rolling the bass out because you're turning down the volume but the treble is still getting through. I don't think this circuit moves the frequency of the high-pass filter, but it'll trick your ear into thinking that that's what you're doing.

 

[tartanphantom]

If you're looking to create a bass or mid rolloff circuit, you would wire similar to the traditional treble cut tone control circuit, but use an RF choke or inductance coil in place of the capacitor. Coils & chokes are measured in henries (and microhenries) instead of microfarads. They will restrict low frequencies and allow higher frequencies to pass through the circuit.

 

[Average Joe]

Fenderr's TBX control roll bass off on one side of its travel. It's got a middle detent -turn it one way and it's the regular treble roll off, turn the other way and it cuts bass. Quite useful