Optics related and Audio/ Guitar related tech info pages
Introduction
This is a collection of semi random tech info pages. Most of it is/will be about guitar/ audio technology and a bit about physics & electronics.The site is still under construction, more info will followGuitar electronics / Audio related topics:
Triode calculator
An online calculator for the common cathode amplifier, the basic voltage amplifier using the triode electron tube. Demonstrates matrix inversion of complex numbers in javascript and linlog / loglog plots using the html5 canvas.
Sallen Key Lowpass filter transfer function plotter
Calculates a 2nd order lowpass and plots the transfer function using javascript and the HTML5 canvas.
Soft clipping overdrive using a Spin Semiconductor DSP
The challenge here was to create a 'organic' and 'warm' overdrive guitar sound using a Digital Signal Processor. This page explains how it's done and you can listen to the result.
Ultimate simple measurement of the DC bias of electron tube amplifiers
There are several ways to adjust the DC bias current of electron tube amplifiers and just as many opinions about how to do it right. On this page, a totally different method is explained. It's simple and easy!
Sound comparison of EL34, EL34L and KT77
A youtube demo to systematically compare these JJ manufactured pentodes / beam power tetrode.
Optics
Pulse dispersion
Pulse stretching due to dispersion is a phenomenon that occurs in various situations: acoustic pulses (for instance seismic pulses), electric pulses in cables or electric circuits, optical pulses etc. Here's a Jupyter notebook Python script that calculates the dispersion of a femtosecond optical pulse as it travels through a dispersive medium like BK7 glass. A textfile for bulk refractive index vs. wavelength can be applied for the material of interest.
Prisms
An online calculator for the angles at which light that passes through a prism
Waveplates
An online calculator for the polarization states of a bundle that passes through wave plates and polarizers