Tube Screamer tone control

[MmmPedals]

The Tube Screamer has an active tone control which adds up to 6db treble boost. But the tone control follows a 6db treble roll off  .
What is the advantage of this over a passive tone control without the roll off?

[ppaappoo]

The Tube Screamer has an active tone control which adds up to 6db treble boost. But the tone control follows a 6db treble roll off  .
What is the advantage of this over a passive tone control without the roll off?

I like more with a treble roll off control. Or may be the proco rat tone control.

[MmmPedals]

My intention is to replace the existing active control with a bass or mids control and just use a passive treble control in place of the stock one. I want to know what if any difference there would be in the treble control.

[ayayay!]

Take a look at the Boss SD-1 tone control.   

[MmmPedals]

Okay. What compelled Ibanez to use an active control? There must be a better use of the second half of the Opamp.

[ayayay!]

It's not so much an active tone control (although it is, as evidenced by the insane mid boost when turning the pot CW, but like I said the SD-1 doesn't do that and it's the same setup) as it is a gain recovery stage.  Signal is clipped, then dumbed down even more by a tone control after it.  Needs something to juice it back up and it sets thing up to apply proper output impedance.

[MmmPedals]

The tube screamer has the the treble roll off in there so it loses the volume anyway. why not just make it a passive control?
There is an output buffer so the impedance wouldn't be an issue.

[earthtonesaudio]

Maybe they had a million W-taper pots and needed to find a use for them...?

[ayayay!]

The tube screamer has the the treble roll off in there so it loses the volume anyway. why not just make it a passive control?
There is an output buffer so the impedance wouldn't be an issue.

Mmmm, I see what you're saying but it's not quite right.  It loses the volume because of what it's shunting to ground (big cap there...)  It still needs/likes that gain recovery after the tone filter.  You'll need the volume.  I mean, I guess if you're saying 'why not just use something like a SWTC?' then by all means try it, but you'll see you'll still want the 2nd half of that opamp doing its current job.   What I'm trying to say is it's a kind of dual purpose control.  Kind of active, yes, but the more you feed into the 2nd half of the opamp (from the tone control) the louder it gets because of the opamp, not the other way around.  In other words, I think it's crappy too, but that's the selection of values for the tone control, which is why I prefer the SD-1's values.  

As far as the output impedance, yes that does matter between stages.  Case in point, bufferless Tube Screamers like the Lovepedal Eternity, for example, have no output buffer.  Stage to stage must be controlled.  The output buffer you're referencing is more of a necessary evil because of the switching circuit.