DIY amplifier for boombox

June 10th, 2009

Me and my friends wanted some sound in our camp at this years Roskilde Festival so I set out to build us a boombox.

I ordered an amp6-basic kit from 41hz.com because of the many recommendations I have read and because the kit comes with mostly through hole components and is relatively easy to solder.

After soldering i mounted the amp in an aluminum plate from an recycled aluminum profile. It was quite a revelation to discover how forgiving aluminum is as a material. I have added a 50k Ohm stereo log pot for volume control a stereo minijack input and a switch that i wired to the 12V input since it didn’t seem to produce any noticeably larger turn on thumbs than the sleep jumper. I somehow managed to reverse the volume pot, meaning you turn it up rotating against the clock, and the power level seems to max out when turned half way around. It is not important for this amp, but for the next one I will look into improving the volume control, perhaps using an attenuator and an active preamplifier – can anyone point me to a good DIY volume control or preamplifier guide/advice? Currently the amp is powered by a screw machine battery but we are planning to bring a car battery to power it during the upcoming festival.

The amp sounds great, and is loud enough even through 8 Ohm, and being a class T amp it is very efficient thus giving us many hours of music on a recharge.

Next up is encasing the amp and speakers providing it with weather protection and fitting it with wheels, i am hoping to find some large bicycle wheels. Right now i am considering a light design using two 8 Ohm compact speakers, or using 2 heavier 4 Ohm speakers, they are very old and rated to 15W RMS which is not quite as much as the 25W RMS the amp outputs through 4 Ohm, I am not sure if this will be a problem.

On a side-note fooling around with electronics for the past 6 months i have been wondering why we are not all running with 12V DC as mains. I suspect there are a few reasonable arguments but i haven’t been able to find them.

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Posted in electronics | 2 Comments »

Words I am attached to

June 10th, 2009

A quick list of words, metaphors and terms that I have a strong attachment to, meaning they are deeply embedded in my mind, they bring up emotions, memories, feelings, thoughts or are directly connected to physical motion, often words that I use a lot. These attachments are in fact my definitions, they make out what words mean to me. So i thought it would be interesting to write down a few of the words that would first spring to mind. The strongest attachments though, I believe are subconscius subconscious.

abstraction, rational, scientific, inherent, absolute, relative, perspective, horizon, perception, decentralized, google, open source, transparent, translucent, democracy, quality, bicycle, electronics, architecture, design, aesthetics, urban, evolution, mind, contradiction, moral, development, simplicity, minimalism, ecology, sustainability, linux, unix, mac, windows, IE, web2.0, Second Life, neural, implicit, embedded, virtual reality, web standards, python, php, money, espresso, gastronomy, autonomy, effective, waste, organized, TED, spiritual, god, …

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Object Oriented WP plugin structure

July 18th, 2008

When searching the web for WordPress plugin tutorials and introductions the vast majority utilizes procedural programming. However having recently discovered Object Oriented programming in PHP 5 i decided to take another approach to both plugins and themes.

When encapsulating plugins or parts of your themes in classes, you create a container for variable, constant and function names thus avoiding name clashes with the core or with other plugins. You can also encapsulate your class in a statement checking if the class already exists to ensure that in the rare case of a name collision your plugin will not initialize and crash the WordPress installation.

Here is a simple example 

< ?php
// Plugin Name: Text Barking Dog



if (!class_exists('OurWpPluginDog')) {
    class OurWpPluginDog {
        function __construct() {
            $this->text = "wuff wuff";
        }
        function bark() {
            echo '';
        }
    }
    $dog = new OurWpPluginDog;
    add_action('wp_footer', array(&$dog, 'bark'));
}

This plugin will insert “wuff wuff” as an html comment at the hook wp_footer. The __construct function runs when the class is constructed you can also place your actions and filters here, if you do you simply reference array(&$this … instead.

Object oriented programming encourages DRY – it simply makes it more convenient to reuse your code. As your plugin grows you will also find it easier to get an overview of the code.

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Posted in Wordpress | 3 Comments »

Linux for the future

July 9th, 2008

About a year ago i bought a Macbook Pro and made the change to Mac OS X from Windows, and for a while i became a true Mac-Zealot. Then as now i was enthusiastic about open source software and hell i discovered a lot of small and nifty applications for OS X. However more often than not i found that the best Open Source applications was made natively for Linux and then ported to Mac, and the best games were made natively for windows and often not ported at all. At first i was perplexed that software manufacturers did not develop for Mac. But as i became increasingly aware of Apples company structure, it wasn’t startling. In How Apple Got Everything Right By Doing Everything Wrong Wired describes the Apple company as the Evil Genius in vivid detail. I won’t go into further detail on the article but i truly recommend you read it, especially if you are a dedicated Apple fan the article can put things in perspective.

Motivated by moral reasons i finally installed Ubuntu on my Macbook Pro. The change did not involve major complications. In fact the synaptic package manager puts more order into your computer than any drag and drop interface and gives you access to an ocean of amazing Open Source utilities making ubuntu a good choice for both the casual and the professional user. Unless you are a hardcore gamer ubuntu will most likely more than suit your needs.

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Posted in Open Source | 1 Comment »

Open Movie

June 17th, 2008

This week i recieved my preordered copy of Big Buck Bunny. A video production by the Peach open movie project. The movie tells the story of a giant hearthful rabbit taking revenge against three rodents who harass him. The storyline is alright, and the general quality is stunning. However the aspiring aspect of the project is the philosophy behind.

The two open movie projects, Orange and Peach respectively have pionered the world of open movie production. The Orange movie project released Elephants Dream as the worlds first open movie and the same team supported by the Blender foundation now gave us Big Buck Bunny. Both projects are made entirely with open source graphics software such as Blender, and with all production files freely available to use however you please, under a Creative Commons license.

Traditionally you need to watch the mandatory disclaimers and copyright notices before the action starts. That is; if you are lucky enough that the region code of the dvd matches that of your drive. In short the paranoid industry spends enormous amounts of resources on lawyers and copy protection. Protectiong themselves from who? One might be right to ask.

The open movie projects are a breath of life to the industry and a prove of concept that professional movie production and animation can be accomplished with an open phillosophy utilizing only open source software.

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Launching cenario.com

May 11th, 2008

I have worked with geist on this website for the 3D visualization studio CENARIO. The project is the largest I have taken upon me in web development to this date and i have worked with several technologies that i have not utilized professionally before. The site is developed in Zend framework and uses the amazing mootools for the frontend. The site is hosted on Media Temples (dv).

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Getting further with bamboo

April 23rd, 2008

Along with ten other wonderful projects i was accepted for the next round in the Design for an Eco-friendly Community architectural competition about sustainable bamboo constructions.

With no experience as an architect i have come along way. From believing bamboo resists gravity, to actually understand the materials properties in the real world. I have read a great deal about bamboo, its structural properties and different uses. Bamboo is the steel of nature, and the ways in which it can be used continuously amazes me.

For my project i have worked mainly with woven bamboo. Sophisticated weaving techniques allows you to weave bamboo in all imaginable shapes. For the framework i utilize heat bended bamboo. The structure positioned in the treetops of the jungle is supported by long structural elements of four black bamboo canes connected with steel knobs. The structural elements are mounted in a concrete foundation in order to avoid moist damage to the canes. Several of the elements are inspired by the prototypes presented by Bamboo Lab a research project on bamboo as a building material.

I have tried to investigate more sophisticated ways of handling bamboo in order to showcase its potential as more than a Tiki Hut material but a beautiful element in contemporary architecture.

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Posted in Architecture, Second Life | No Comments »

Design for an Eco-friendly Community

March 4th, 2008

Accident Designs just enlisted in this competition arranged by arcspace.com and ecolandnow.com, in collaboration with INBAR – International Network for Bamboo and Rattan.
Read more!

Bamboo …!

The competition is a great opportunity for me to unite my interest and ideas regarding architecture with my expertise in Second Life. I am looking forward to be a part of it and i am sure i will learn a lot in the process.

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Virtual Moves (is) Open Source

March 3rd, 2008

This friday we had the last reception on the Danish National Gallery where the final two artworks were launched. I have spend some time organizing and refining the scripts which i have developed for the installations in Second Life. Jacob Sikker Remin submitted his work in Arduino and Processing for memory SLot. I have encouraged all of the artists to submit there own work as well. Read the rest of this entry »

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Posted in Open Source, Second Life | No Comments »

Magnatune, We are not evil

February 19th, 2008

Why are they not evil? – see for yourself: magnatune.com They are present in Second Life: http://magnatune.com/info/second_life

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