STAND-ALONE tone control PEDAL. Does it exist?

[A Bass And Its Boy]

Isn't a wah basically stand-alone tone pedal?

 

[BismarckHerring]

Excellent one knob tone plus boost if you need it.

My Zoom pedals (MS-60B and B1-Four) both have compressors they call DynaComp (its a sim of something by MXR)

I use it as the second compressor in my line. It has a tone knob on it and I use it all the time. It's quite handy, actually

I'm pretty sure these are different types of controls than the passive tone control on a bass. These are tilt controls that have a center frequency and boost lower frequencies and cut higher frequencies or vice versa. A passive tone control cuts frequencies above a variable cutoff frequency.

 

[MartinB]

Thread 'How Tone controls work'

Mar 18, 2024

On a lot of threads, I end up trying to explain to people how passive tone controls on basses work (spoiler - they don't work like you think they do). Though they are simple circuits, the reactive nature of the pickups feeding them results in behavior you wouldn't really expect - they don't just "turn down the treble". Anyway, having designed circuits and other pro audio stuff for a living, Spice simulations (they way we predict circuit behavior before building prototypes) are in my wheelhouse. I won't go into tall the details of this (you need to characterize the pickups, which is a non-...

• micguy
• Replies: 165
• Forum: Pickups & Electronics [BG]

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[mcnach]

I have many active instruments that have boost/cut for 2 or 3 EQ bands. Normally these controls effect specific bass mid or treb frequencies. BUT if i want a tone control effect to span the freq spectrum/entire signal, identical to a passive tone control on a passive bass, i cannot find one. Now, I have a Sadowsky, and a Sire with a John East J-tone pre that both offer an onboard passive tone control in addition to the active circuit with bass/treb boost only or boost/cut. But my other basses do not offer such features. So my question is……..

Is there a pedal I can add to my pedalboard that has a Passive tone control for use with my other active instruments? I've had several active basses that simply do not warm up due to a lack of the ability to roll back the tone. Even with the treble control completely cut, the harsh frequencies I'm trying to roll off cannot be quelled…

So,does such a magic pedal exist?

Not exactly the same, but close enough for R&R, a low pass filter pedal is what I've been using for the same purposes. Something like this:#

Low Pass Filter | Broughton Audio

 

[mcnach]

The Broughton appears to be frequency specific ( which is not really what I'm looking for) the Saturnworks seems to be the solution. I just need to make sure it's usable with an active circuit coming into It. I imagine it is, just gonna check. Much thanks for the help.

It cuts frequencies ABOVE whatever frequency you have it set at, just like a passive control cuts frequencies above a certain frequency too (although the passive control can have a small 'bump' right above the threshold frequency). In practice it's the closest to a passive tone control.

 

[ceetee]

Using a loooooooooonger cable on the bass in question should work to some extend.

 

[el murdoque]

Here's my terrible layman electronics explanation, seasoned with hands-on experience.

1. The terms EQ and Filter are often used in a way that makes you think they are different things. An EQ is nothing but a group of filters.

2. The term Low Pass Filter sounds like you set it to 1000 Hz and then there will be a harsh cut. a 999Hz sine wave passes full strength, and a 1001Hz sine wave will be completely gone. That is not the case. A low pass filter usually operates with a specified amount, given in dB/oct. A 6 dB//oct filter, set to 440Hz, would reduce a 880Hz signal by 6dB.

The tone knob is a passive low pass filter. When fully turned up, you'll have zero resistance from it, giving you the full tone. As you turn it down, you get more and more resistance from the pot, and your signal has to pass through there. The treble is the weakest part of the herd, and that gets culled first. With the tone knob all the way down, only the strongest bit of the signal, the bass register, may pass.

A low pass filter will do more or less the same thing.

However, there can be a difference, depending on the gear used.

In a passive bass guitar, you often find a resonant peak that gets created just before the pickup's natural drop off in the treble.
When using the tone knob, you shift that resonant peak downwards as you turn the knob.
When using an external low pass filter, that peak won't move. It simply gets eaten by the filter.

When comparing the tone knobs of several of my passive bass guitars with the broughton LPF pedal, I have the feeling that the Pedal does have a bit of a steeper slope and feels cleaner, more surgical. They are essentially doing the same thing, but they sound slightly different, depending on how you use them.

 

[HueyFreeman]

The Broughton LPF is a great utility pedal, but it doesn't operate as a passive tone control does.

Read post #23. It links to @micguy excellent thread that explains what passive tone controls do.

There is a resonant bump at the cutoff frequency when tone is dimed. The first half of rolling off tone reduces the peak, not the frequency. The cutoff frequency doesn't move until the tone control is roughly half of the controls travel.

 

[Slevage]

Yup. I get that the frequency being rolled off is dictated by the capacitor value, but the effect is far less specific, for lack of a better word, than say, a slide on my bass 10, which is NOT a soft knee EQ. So i was hoping a traditional tone circuit similar to the ones in my J-Tone or Sadowsky pre, were available as a pedal.

You should actually measure and plot the output of what you like. Once you have the data, it might be possible to recreate that with something already on the market. There's good chance that shifting and selecting frequencies with accuracy will do it. There is an exact science to what you want so there's a solution.

 

[DangYankee]

I was recently on the hunt for something similar, the [Invalid or Expired Link Removed]is pretty close to what you're looking for. It's literally the tone control from their onboard preamp in pedal format.

 

[beans-on-toast]

i own a whirlwind bass ten EQ, but again, it doesn't seem to have the same effect as a passive tone control. I am also not looking to boost anything. I'm simply trying to emulate the effect the VTC creates on the active circuit. I can boost the treble on sadowsky slightly , then roll back the VTC and get the sound Im searching for. Id like to replicate that experience with my Streamer and Ibanez.

A passive tone control comes with a loss just for being in the circuit. Some gain to bring the signal level up to the initial level can be a good thing. That's what active tone controls do., provide a small boost. Dealing it in right is important. Note that not all EQ's are alike in the way that they affect your tone.

Since you're needs are very specific, I think that you'll have to try out some products with your basses.

A phone RTA audio spectrum analyzer app might help to visualize what is going on. One example:

Spectrum Analyzer RTA App - App Store

Download Spectrum Analyzer RTA by ONYX Apps on the App Store. See screenshots, ratings and reviews, user tips and more apps like Spectrum Analyzer RTA.

apps.apple.com

 

[pb9717]

One thing I'll call out - if you really like a passive tone you may not like it AFTER your onboard active preamp. Preamps like a Sadowsky VTC the tone is before the preamp, so the signal going into the pre has the tone rolled off and then you can boost certain frequencies. It's a different signal path and sound if your onboard pre is acting on the full signal of your pickups AND THEN you have an EQ rolling off tone later.

I love the Sadowksy preamps because of that signal routing of being able to roll off the highs before it hits the pre and then having a boost only after.

I had no idea.

It will be impossible to put the tone control before the active circuit for the instruments that are already sending an active signal.

 

[groovaholic]

Is there a pedal I can add to my pedalboard that has a Passive tone control for use with my other active instruments?

I'm not aware of one.

It would be a simple device - possibly even be a passive pedal (no power source required) - so I can't imagine it would be a hot seller.
...hence not very profitable, hence not offered on the market...

You'd essentially just need a pedal enclosure, a stomp switch, a capacitor, a potentiometer, and two 1/4" jacks.

The circuit would be identical to a passive tone control in a bass, but the values would be different: the capacitor would be approximately 10-20x larger (.5 to 1uF rather than the typical .047uF) and the tone pot would be 10-20x smaller (probably 25k rather than the 250-500k you see in a passive bass).

That would allow you to passively attenuate high frequencies.

But as others have noted, another major aspect of the passive tone control is how it capacitively loads the pickups.
That's what gives the resonant peak near the cutoff point that makes things seem fatter.
And that part of the interaction would be much more complicated to recreate when fed with active electronics that buffer the output signal.

 

[agedhorse]

I'm unfamiliar with the term "Active" tone control. My only experience with Tone controls are on passive , or active basses that add them, i.e the sadowsky VTC or John East pre's. That offer that capability. Please expound if you would……

Active tone controls are just as common as passive tone controls, in fact most active basses have active tone controls.

View attachment 7346071
The broughton also appears to provide the ability to select the capacitor value, but does not provide a POT to control the amount of tone reduction the pedal provides. ( unless I'm not seeing something)

That's not how a low pass filter works.

Isn't a wah basically stand-alone tone pedal?

No, not even close. A wah is a sweepable bandpass filter, sometimes combined with a low pass filter.

Here's my terrible layman electronics explanation, seasoned with hands-on experience.

1. The terms EQ and Filter are often used in a way that makes you think they are different things. An EQ is nothing but a group of filters.

2. The term Low Pass Filter sounds like you set it to 1000 Hz and then there will be a harsh cut. a 999Hz sine wave passes full strength, and a 1001Hz sine wave will be completely gone. That is not the case. A low pass filter usually operates with a specified amount, given in dB/oct. A 6 dB//oct filter, set to 440Hz, would reduce a 880Hz signal by 6dB.

The tone knob is a passive low pass filter. When fully turned up, you'll have zero resistance from it, giving you the full tone. As you turn it down, you get more and more resistance from the pot, and your signal has to pass through there. The treble is the weakest part of the herd, and that gets culled first. With the tone knob all the way down, only the strongest bit of the signal, the bass register, may pass.

A low pass filter will do more or less the same thing.

However, there can be a difference, depending on the gear used.

In a passive bass guitar, you often find a resonant peak that gets created just before the pickup's natural drop off in the treble.
When using the tone knob, you shift that resonant peak downwards as you turn the knob.
When using an external low pass filter, that peak won't move. It simply gets eaten by the filter.

When comparing the tone knobs of several of my passive bass guitars with the broughton LPF pedal, I have the feeling that the Pedal does have a bit of a steeper slope and feels cleaner, more surgical. They are essentially doing the same thing, but they sound slightly different, depending on how you use them.

Good explanation.

Here's an example of an eq/filter pedal that combines an active high pass filter with an active low pass filter and 5 bandpass cut-boost filters.

RE/Q - DUAL FUNCTION EQUALIZATION PEDAL - Genzler Amplification

The re/Q™ DUAL FUNCTION EQ PEDAL is a low noise, ALL ANALOG multi-function HIGH PASS FILTER – LOW PASS FILTER and 5 BAND EQ pedal that gives the player complete tonal control over the cut-off of the extreme low and high frequencies, plus 5 bands of peak-dip equalization.

genzleramplification.com

The advantage of active filters is that you can get higher slopes, Q's and both cut-boost functions.

 

[Lo-E]

I had no idea.

It will be impossible to put the tone control before the active circuit for the instruments that are already sending an active signal.

You could go with a very simplified, passive tone control in a box using a 25K pot and a 0.1uF capacitor (these are fairly common values when using active pickups with a passive tone control) and it will get you in the ballpark for very little money but, as @BGroovy points out, it won't really behave exactly as it would if it were a passive tone placed before the preamp. It would behave similarly, though and might be just the ticket.
The whole thing could be built for about 25 or 30 bucks.

 

[micguy]

I have many active instruments that have boost/cut for 2 or 3 EQ bands. Normally these controls effect specific bass mid or treb frequencies. BUT if i want a tone control effect to span the freq spectrum/entire signal, identical to a passive tone control on a passive bass, i cannot find one. Now, I have a Sadowsky, and a Sire with a John East J-tone pre that both offer an onboard passive tone control in addition to the active circuit with bass/treb boost only or boost/cut. But my other basses do not offer such features. So my question is……..

Is there a pedal I can add to my pedalboard that has a Passive tone control for use with my other active instruments? I've had several active basses that simply do not warm up due to a lack of the ability to roll back the tone. Even with the treble control completely cut, the harsh frequencies I'm trying to roll off cannot be quelled…

So,does such a magic pedal exist?

You can't make a pedal do what a passive tone control in a bass does - the cable is a load that is after the pot in the bass. If you try to do that in a pedal on the other end of the cable, the cable capacitance is in the wrong place in the circuit. You can make a pedal where it mimics the "tone off" position fairly well (that's just a capacitor in a box), but "half tone" and above, it's not gonna work the same.

 

[micguy]

Active tone controls are just as common as passive tone controls, in fact most active basses have active tone controls.

Yes - most active basses have passive pickups, a buffer stage somewhere, and active tone controls. EMG's pickups are the notable exception, where the pickup has circuitry in it*, but most everything else is a passive pickups and active circuitry. If a bass has an active/passive switch, it definitely has passive pickups.

*There is actually a passive pickup in an EMG pickup, but there's a buffer in the housing as well, and the way it's wired means you can't get a signal out of it without power.

 

[Smooth_bass88]

this question pops up pretty regularly around here. At this point it's honestly surprising that someone doesn't make and market a tone control knob in pedal format. It would probably sell like crazy. I would totally buy one.

I absolutely prefer my passive basses, and on the rare occasion that I use one of my active ones, I always run it in passive mode. I miss not being able to roll back the tone knob

 

[agedhorse]

this question pops up pretty regularly around here. At this point it's honestly surprising that someone doesn't make and market a tone control knob in pedal format. It would probably sell like crazy. I would totally buy one.

I absolutely prefer my passive basses, and on the rare occasion that I use one of my active ones, I always run it in passive mode. I miss not being able to roll back the tone knob

Or it wouldn't sell at all... just sayin'.

 

[Lo-E]

It would probably sell like crazy. I would totally buy one.

Only if it worked the same way as a tone control does in a passive circuit.

The problem is that it can't. It can do something similar in terms of rolling off treble but it won't affect the resonant frequency of the pickup or pickups because there's buffering in between. Because of that buffering, it wouldn't offer very much advantage (if any) over just turning down an active treble knob.

It's a great idea on paper but it doesn't really fly in practice. The best it would be is a "sort of like a passive tone control." It would work; it would roll off treble, but all the interactive properties of passive circuits would be missing and those properties are what a lot of people like about passive tone controls.