A Brief Hobbyist Primer on Effects Pedal Circuits Fixed Resistors - in collaboration with Drunk Beaver's Vitalii Bobrov
External
Voltage Divider Calculator
Inputs
V
Solve for Vin
Solve for R1
Solve for R2
Solve for
Solve for: Calculated from Vin 9 V, R1 10 kΩ and R2 10 kΩ
Result
Standard values
Vout
4.5 V
Advanced
450 µA
5 kΩ
0.5 · -6.02 dB
Schematic
Formula
Vout equals Vin times R2 divided by R1 plus R2.
Vout 4.5 volts
About this calculator
Design and verify voltage divider circuits with forward and reverse resistor solving. Defaults to standard 9V pedal power supplies with instant E24 snapping and bias network impedance diagnostics.
Frequently asked questions
What is the voltage divider formula?
The output voltage across R2 is given by Vout = Vin * (R2 / (R1 + R2)). This formula assumes negligible load current drawn from the divider output.
Why is a 9V to 4.5V voltage divider common in guitar pedals?
Single-supply operational amplifiers in 9V guitar pedals require a 4.5V half-supply bias voltage (Vref) so the audio signal can swing symmetrically without clipping.
How does output impedance affect a voltage divider?
The effective AC output impedance of a voltage divider is R1 in parallel with R2: Zout = (R1 * R2) / (R1 + R2). Higher impedance saves battery power but is more vulnerable to load sagging.
Can a passive voltage divider step up voltage?
No. A passive resistive voltage divider can only attenuate voltage, meaning Vout must always be strictly between 0V and Vin.
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