Pushing the boundaries. Of what I have no idea.
I built the Tesla Fuzz especially for a collaboration between Arc Attack and some talented metal guitarists. And here they are!
Finally got round to fixing the server yet again
This was made from oak battens, a suspension kit for a 600x600mm LED panel, and lamp holders, cable and ceiling rose from Creative Cables.
I wanted the Edison bulb look, but needed it to run off low voltage due to my sketchy wiring. I found some 12V E27 LED bulbs on EBay, but the choice was much more limited than mains voltage ones, and they had to ship from China. The ones I bought are completely unregulated so the brightness varies drastically with voltage. See Big Clive’s teardown of the same bulb.
I ended up using them in 3 series pairs with a regulated 24V supply from a boost converter hidden in the ceiling rose.
DIY boost converter made with a LM2576HV
The Crown SXA has had black power transformers and silver/rust coloured output transformers for like a decade now 😉 The black Hammerite spray paint is great.
One of the joys of living in an old house is dodgy wiring. Another joy is ornate lath and plaster ceilings that might collapse at any minute. 🙂 My problem is a combination of the two. The overhead lights in most rooms are powered by 1930s vintage rubber and cloth covered wiring that can’t be replaced without trashing the ceilings.
As a token gesture to electrical safety, I added a RCD to the lighting circuit, and believe it or not it started tripping at random. This left me with a few options:
Stop using the ceiling lights altogether
Have them rewired and the ceilings replastered
Run the lighting circuit off a lower voltage that wouldn’t tax the ancient rubber and cloth insulation.
A lower voltage would of course limit the power that could be delivered before overloading the wiring. So the second part of the plan would be to replace the light fittings for LEDs to achieve a reasonable light output with less power.
I decided to go for 12V (in hindsight 24 would have been better- I ended up replacing the power supply with a 15V one as a compromise…)
First step was to source a reputable brand of power supply festooned with safety approvals. It will be left on 24/7 unattended, and it would be ironic to go to these lengths to avoid the wiring catching fire, only for the PSU to catch fire. 🙂
I bought a few 600x600mm LED panel lights from TLC Electrical, and chucked the 240V drivers that came with them for some 12V drivers from Ebay.
They are still plenty bright enough.
The power supply was mounted next to the consumer unit and connected to the existing 240V lighting circuit with a FCU.
Oh dear… At this point I realised the thickness of the old wires was mostly insulation and the actual copper cross section was puny. To the point where a 11 amp power supply could potentially overheat them if one of the light fittings shorted out, leaving us no better off in terms of safety than before.
I connected it up anyway 🙂
The first of the new light fittings in place
The other light fittings were modified with bodges like this
Later I added some fuses to address the issue of the PSU being able to overheat the wiring.
(footnote: this is still working in 2021 and I made some funky low voltage light fittings 🙂 )
8″ speakers never really did anything for me, so I decided to wedge a 10″ into the Ninja Corvette.
It was just possible by carefully chiselling away parts of the cabinet.
It sounds a lot better than the 8″. Unfortunately I have no idea how to make a good grill for it now!
My new Tesla coil “Odin” is up and running.
Ever since the Raspberry Pi came out, I’ve been experimenting with its audio capabilities. The latest audio gizmo available for it is the Wolfson Pi Audio Card, which promises 24 bit, 192kHz recording and playback, with analog and digital I/O, for a very reasonable price. So of course I ordered one straight away. 🙂
After waiting a month I finally got my hands on it. The software installation is somewhat unclear so I will document what I did here. I didn’t want to use the Wolfson official image as it was a massive 8GB download. I started with a copy of the image that I developed for PiTunes, and applied this patch to it, which adds the Wolfson kernel and the support files for the audio card. I then changed mpd.conf to use audio output device hw0,0 (it was previously 1,0 for the USB audio device) and added a call to SPDIF_playback.sh in my .bash_login file, to set the card up for digital output.
I also removed the invocation of pikeyd from /etc/rc.local, as the keypad and encoder were not present. They can’t be used anyway, since the Wolfson audio card hogs all of the GPIO pins. It doesn’t really matter, as MPD can always be controlled remotely.
On firing this up, I was surprised to find that it worked first time! 🙂 I verified the output to be bit perfect at 24 bit, 96kHz. This is possibly the best value for money HD audio source you can get anywhere: you should be able to pick up a Raspberry Pi, a Wolfson Audio Card, a wifi dongle and a hard disk for under £100.
