# Help with frequency response of guitar tone circuit

1. Mar 29, 2006

### dimensionless

The circuit of interest is the basic circuit for a Fender Stratocaster guitar. A diagram can be found at http://www.seymourduncan.com/support/schematics/S_1singlecoil_1vol_1tone.html . Basically an electric guitar works by vibrating a metal string in a magnetic field. This in turn causes a current to be generated in the an inductor that is wrapped around the magnet.

What I'm trying to do is find the frequency response of this circuit. Whenever I try to calculate the transfer function for this circuit I get

$$TF = 1$$.

When I try to calculate the total impedance for this circuit I get

$$Z_{total} = \frac{Z_{1}Z_{2}}{Z_{1}+Z_{2}} = \frac{(R_{1} - j\frac{1}{\omega C})R_{2}}{R_{1}-j \frac{1}{\omega C}+R_{2}}$$

where
$$Z_{1} = R_{1} - j \omega C$$ and $$Z_{2} = R_{2}$$.

To find the transfer function I calculate

$$TF = \frac{V_{in}}{V_{out}} = 1$$.

This is obviously incorrect, but I don't know where my mistake is. Is my diagram correct?

Last edited: Mar 29, 2006
2. Mar 29, 2006

### dimensionless

My post is a litle confusing. I had an ACII diagram, but it did not get rendered the way I wnated it to. R2 is the volume pot, and R1 is the tone pot.