What exactly do Tonestack position change?

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What does Tonestack position change?

So I been messing around with the tonestack positions, and can clearly hear a difference, but would like to know what exactly is this changing as far as tone controls etc? Does this change the position of preamp tubes, or remove or add tone controls? Just trying to figure it out.

I always look up wiki but nothing it available on this subject.

Also, if I were to use a Plexi 50watt jump model, but wanted a Blankenship tonestack, which one is that in the Axe?
 
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It changes the location of the tone controls in the amp circuit. pre-gain, post-gain, etc.
 
It changes the location of the tone controls in the amp circuit. pre-gain, post-gain, etc.

Hmmmm. That just kind of confused me a bit more. Could you give some examples, of say a Plexi in all the different positions and how the tone controls would react or be placed?
 
Different amp designs have the tonestack in different positions in the amp circuit. I believe Fender it is typically before the gain stages and Marshall it is typically after. I could have it backwards though, I only know enough to be dangerous.

Here is a picture that Cliff shared in one of his tech notes post. The different tonestack positions essentially fit in around the gain stages, after the input trim.

amp_block_gains.jpg


The best thing you can do is experiment. There is no 'wrong' setting that will damage the amp in the Axe-FX.
 

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So like tonestack pre= amp relies on preamp tubes. Post=Powertubes, and Mid=? End=?

But yeah, I do experiment and lucky for us all we can get away with this in the Axe. Just trying to get a better understanding so when I do play around with these I know what's going on and wont spend a lot of time on something that isn't going to fix my taste.
 
Think of it as an EQ pedal. EQ pedal before the amp can affect how much certain frequencies get distorted, EQ after the amp, such as on the mixing desk doesn't change distortion, but changes the overall shape of the sound and what ranges are enhanced/reduced

Shaping the sound with a tone stack before a preamp vs before a power amp sound different and affect the tone differently

Just move it around and listen to the differences.
 
The way I've always looked at it is this...

Amps have Bass, Middle, Treble, Volume...etc

Each amp's EQ knobs all hit different frequencies and spots...

So- using the tone stacks puts the unique sweeps and frequcies from one amp into another.

So you could play a Mesa Boogie Rectifier amp with the Treble/Mid/Bass knobs of a JCM800.

....I think...idk
 
The tone stack is the main bass/mid/treble controls of your amp. It's called a tone stack because these controls, and the circuits that support them, are close to each other, both physically and electrically. On a schematic diagram, they often look like a stack of controls.


The basic signal chain of a guitar amp looks like this:
[Input Jack] -->-- [Preamp] -->--- [Power Amp] -->-- [Speaker]​


Tone Location means where you put the tone stack in that circuit. To find out, let's look at the manual...

The Manual said:
TONE LOCATION – This control lets you change the location of the tone stack. “PRE” places the tone stack at the input to the preamp, “POST” places the stack between the preamp and power amp. “MID” places it between the last two triode stages, and “END” places it after the power amp (which is physically impossible with a real amp). Defaults to an appropriate value whenever you change the amp TYPE.
 
So like tonestack pre= amp relies on preamp tubes. Post=Powertubes, and Mid=? End=?

But yeah, I do experiment and lucky for us all we can get away with this in the Axe. Just trying to get a better understanding so when I do play around with these I know what's going on and wont spend a lot of time on something that isn't going to fix my taste.

It's nothing to do with tubes. The tone circuit is a collection of capacitors, inductors and variable resistors that provide the treble, mid and bass controls. On different amps they are placed at different points in the circuit. Each position gives a subtly different response to knob fiddling. Experimentation and thus the gaining of knowledge and experience is the only path to true enlightenment, or whatever...
 
Hey thanks a lot guys!! I think I got the ideal now, and might have to revisit the manual to see what else I've forgot about. :)
 
Theory over-simplified:

If you have too much bass feeding your saturation/gain stages then it will push the 'tube/valve' into saturation much sooner than if it had been high-frequency boosts. When it's bass-heavy into saturation/gain stages, then the sound will become buzzy/farty and you will lose the advantage of having extra gain stages in effect (because you are no longer subtly adding character with each stage because they will all be overloaded - in effect).

Treble boosting before your saturation/gain stages gives you the benefit of early distortion while still retaining the characteristic coloring of the successive stages. Bass can easily be added later. IIRC, 'Bohemian Rhapsody' was a treble-booster into an AC30 - a lot of distortion and heaviness on that track. ;)
 
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