Jim Marshall crafted guitar amplifier masterpieces without the assistance of computers, software or the Internet... In 1963 "graphical methods" meant drawing Bode plots with a pencil and ruler... Times have changed. ● Master the basics ● Design your amp ● Know it works Amp Design for the 21st Century

calculatorLaunch me!

What does this calculator do?

guitar amp LC lowpass filter

A resistor-capacitor filter is simple and inexpensive. When it needs to supply lots of current, however, it creates a large DC voltage drop, requiring a higher input voltage to achieve the same output. In high-power guitar amplifiers the power tube screens, phase inverter, and preamps draw enough current at full power to make a choke-capacitor filter more economical (at least in the early days of the Fender Bassman and the Marshall JTM45).

An LC filter with the same amount of ripple attenuation and the same size capacitor creates much less DC voltage drop than an RC filter. The key difference is that the inductance of the choke reacts to AC signals but presents, ideally, a short circuit to DC. A real-world choke creates a slight DC voltage drop due to internal winding resistance.

This calculator computes ripple attenuation and DC voltage drop.


Amp Books company logo Amp Books®   About Us | Legal Notice | Contact | Payment & Refund Policy
Copyright © 2005-2024 Amp Books LLC
All Rights Reserved