Optics related and Audio/ Guitar related tech info pages HOME

author: Jeroen Korterik


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 follow

Guitar electronics / Audio related topics:

Triode calculator

triode circuit and plot

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

triode circuit and plot

Calculates a 2nd order lowpass and plots the transfer function using javascript and the HTML5 canvas.

Soft clipping overdrive using a Spin Semiconductor DSP

triode circuit and plot

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

triode circuit and plottriode circuit and plot

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

triode circuit and plot

A youtube demo to systematically compare these JJ manufactured pentodes / beam power tetrode.

Rotary effect for MagOrgans

Coming up: Hosenlander a.k.a. Hans Kemper and Jeroen Korterik have been working on an emulation of a rotary speaker enclosure for stage organs.
The emulation runs on a Digital Signal Processor (DSP). It will be inserted as pcb module in the beautiful organs of the Czech manufacturer magorgans.com. Presets can be defined using a microcontroller with bluetooth or serial interface through javascript on a website.

Optics applets


prism calculator

An online calculator for the angles at which light that passes through a prism


waveplates calculator

An online calculator for the polarization states of a bundle that passes through wave plates and polarizers

Fun stuff / Broekrock related

Here's a collection of installations/tinkering stuff that has been created for the annual Broekrock festival.

Panorama Mestdag

A projector that throws the famous 360deg painting 'Panorama Mesdag' on the inner wall of a 14m diam. silo that previously was used to contain manure slurry.

panorama mestdag broekrock


Demo of a 2D galvo mirror laser projection system that features real time interaction.


Pottery Record Turntable

A pottery turntable was used as rotating base for playing vinyl records.

pottery turntable record player


Idea's and comments are welcome!