Sunday, 4 January 2015

Repair burnt tweeters on B&W DM602 S3 speakers

The second hand market is filled with great audio gear. For example, last week I bought a high end Yamaha amplifier (DSP-A1, 5x 115W RMS) for only 18€ on eBay and just had to clean the volume potentiometer (I used this technique)!

This time I purchased the exceptional B&W DM-602 S3 speakers (on eBay as well) for 91€ with two defective tweeters. In good condition, these speakers sell for 200 to 300€ and replacement tweeters cost 75€ plus shipping so I guessed 91€ was a regular deal at worse.

First thing I did when I got my hands on them was to detach the tweeters: remove the woofer, the tweeter can be removed from the inside by twisting it. As expected, both tweeters were burnt and read 'open circuit' when measuring the resistance at the terminals.

Sunday, 16 November 2014

Configure your WR703n with a switch (or two)


The TP-Link TL-WR703n is a versatile piece of hardware and very handy to have with you when you need WIFI connectivity... The problem is that you need to configure it to fit your needs every time.

This mod aims to re-configure it by the flip of a switch (or two):

  • Choose between WIFI Access point or client.
  • Choose between bridged or NAT/DHCP for WIFI & wired networks.

Wednesday, 22 October 2014

Make your Raspberry pi b more power efficient with a cheap dc step down

Modified RasPi B with a buck converter

The raspberry pi b (the original one, not the b+) uses a linear regulator to bring the 5V down to 3.3V. That's a lot of waste: 33% of the power consumed by the pi is dissipated as heat here! A DC step down (buck converter) would definitely do better than 66% of efficiency. This would certainly improve the stability when running on a weak power supply and make it run much longer if on batteries. Without making any precise calculations, using a buck converter would make the raspberry pi consume somewhere between 20 and 30% less power (efficiency of about 90% vs 66%). Here is how I did it in 10mins for 1.29 USD:

Saturday, 28 June 2014

Building a Wooden Ghettoblaster: Painting faux rust on the speakers (part 4)

This is the final post on how I built my wooden ghettoblaster.

While my previous my three previous building the front face, the enclosure and wiring it all), this post will describe the final touches I brought to this project: painting faux rust and quieting the fan of the cheap Chinese power supply.

Tuesday, 29 April 2014

DUMMYRESEND scam on eBay: You will never receive a replacement for the item that arrived broken

Ten to fifteen years ago people were scared to buy on-line and on on-line auction websites such as eBay, thinking chances of never receiving the ordered items was high without any way to ever see the item or money back.

The web has now evolved and thanks to on-line communities any rip-off is now immediately documented (through direct feedback, blogs and forums). This means that and you usually get something for what you paid for. This does not mean that there are any loopholes and weaknesses in processes that unscrupulous sellers exploit. This article will go through what I call the 'DUMMYRESEND' scam which usually happens when you get a broken item eBay.

Friday, 18 April 2014

Building a Wooden Ghettoblaster: preparing the audio and electrical hardware (part 3)

Almost finished, the speakers still
need painting
This post is the continuation of my two previous posts (building the front face and the enclosure) and I will go through the preparation and wiring of all the electrical and audio equipment in this project. 

Note: there will be another post in the near future about finishing a couple of details (like painting the speakers in faux-rust).

Sunday, 6 April 2014

Set a 'secret' VPN with your second residence using OpenVPN and a cheap TPlink TL-WR703N

This hood is also a wifi
OpenVPN server !
Sometimes you want to connect with a remote NAS or backup service or simply want all your Internet trafic to come from another location.

If you have a second residence with a broadband Internet access, chances are that your Internet provider will supply a preconfigured (and basic) router that fits most people's needs. This router will unfortunately not let you add a VPN server on it ... (even if it were allowed by the ISP terms and conditions) because they are not going to pay for functionalities 99.9% of the population doesn't know and care about.

This post will summarise what you need to have and configure to get you on your way. As well as the best place I found to hide it (tip: it's in the kitchen... ;-):