Some tone control questions .

[seadi123]

How do capacitors effect the tone ? What does a capacitor do when the signal goes through it , bypass it , a resistor bypasses it , a capacitor before a resistor , after a resistor ? What a bout a capacitor going from signal to ground , or from signal to ground bypassed with a resistor ? Also another question . If i would design a simple dirt circuit , would it be better for the tone control to be after or before the dirt stage ? Thanks

[Quackzed]

http://www.diystompboxes.com/wiki/index.php?title=DIY_FAQ
dirt box tone controls usually go after all the distortion gets created, as distortion by its nature creates alot of  high frequencies in addition to the original signal, so people want to 'tame' the high end AFTER they distort the signal, but thats a generalization. its also common to cut some bass frequencies before you distort a signal , to prevent the low frequencies from getting 'very' distorted and dominate the resulting sound.

[Blitz Krieg]

Realize that capacitors function like FREQUENCY DEPENDENT RESISTORS.  This is why capacitors are used in speaker crossovers.

[amptramp]

As the frequency gets higher, a capacitor has less impedance, so you can use capacitors to shape the response of the signal.  If you have capacitive coupling between circuits, the higher the capacitance, the more bass response you get.  If you have a capacitor to ground, this tends to reduce high frequencies and the higher the capacitance, the more signal gets shunted and the frequency at which the effect takes place tends to go down.

The capacitor has an impedance which is like resistance, but the signal going through it is not converted to heat, it is shifted in phase by 90 degrees.  Because of this, when you are analyzing a circuit, the total impedance of a series R-C network is the hypotenuse of a right triangle with resistance and capacitive impedance at right angles to each other.

If you are looking at guitar amp tone controls, duncanamps has a good one that is free as the last item on this page:

http://www.duncanamps.com/software.html

It gives you graphical responses and lets you adjust the controls to see what is happening to the frequency response.

[GibsonGM]

Google "capacitive reactance" - even a simple article about it will probably shed lots of light on the subject!  Amptramp hit on most of it, maybe it would be easier to actually 'see' how it works....duncan's TSC would be great for that, too!  Change cap values and watch the freq. graph....