DIY-DI

This is really a re-visited project. Some time ago I built a little pre-amp to boost the signal from my passive mando pickup (it's in the archives somewhere - check if you wish). Misdirected ambition caused me to create a compact "belt-mounted" device. It was nothing but trouble. Never again will I take on the East in the race towards miniaturisation. I will stick to what the Brits do best: Big fuckoff industrial-looking boxes with hardly anything inside but good in the long run.

Above you can see the business end of the unit. The socket marked "In" goes in and the socket marked "Out" goes out, sort of. This means you can plug things in at any level and they come out at line-level.

I'm really pleased to have discovered the secret of switching the power via the input socket so you don't need a separate power switch. Install a stereo (three-pole) jack socket for the input and connect the neg of the battery to the ring (in the tip/ring/sleeve architecture). When you plug a mono jack into the stereo socket, the sleeve and ring are shorted, the neg ends up where it's supposed to be, and, hey presto, you've got power to the circuit (this is a trick used in most effects pedals). Don't forget to unplug your cable after use else you'll drain your battery.

At the other end of the unit we have the "Smugness" knob. Although one minor side-effect is to make things louder, the primary purpose of this control is to enable geeks of electronic persuasion to treat anyone within earshot to a two-hour explanation of the difference between "gain" and "volume".

For me, the benefit is that I don't have to carry my heavy back line amp to simple sessions. I can plug my mando or bass into anything. Need more signal? You've got it...

New clear energy.

Here at the tank, our top chap Neville has got a cunning new plan to extract the H2 from H2O.
As all you boffins will know, this would mean we could convert our infernal combustion engines to run on the stuff, with the bonus that the exhaust is only water vapour. The only details I am allowed to divulge are that this process will involve a pair of scissors, and a large polished rock borrowed from his mate Macca. Nev assures me that this process will be cheap and highly efficient, and that the patent will be worth quite a bit, and could result in a noble prize.
Neville also believes that this will eventually involve the use of so many buckets of water as to lower sea levels, allowing the reclamation of farm land, and the planting of his favorite trees.
The only predicted drawback is that some atoms may be split in the process, so you may hear some bangs. These will be contained within the tank where we have a very large pot of glue ready.

AP 12.42. 14.3.11.

Modding the Behringer - episode two

Welcome back. A quick update on the repair of the Behringer Ultracoustic ACX900:

One of the failed components on the Behringer was the switched 3-pole jack input on channel 2 which, being plastic, had sheared off at the base of the threaded bit. Our replacement (below) has a metal socket instead of a plastic one. Why this hadn't been fitted in the first place is a secret known only to Behringer. After all, channel 1 has a metal jack so why not channel 2?

Getting the old socket out was a nightmare. This is a double-sided circuit board with plated-through holes and lots of densely packed surface-mount components on the reverse (not visible here). The process of removing the old socket also removed some of the plating, so when we put the new socket in we weren't sure if there was anything left to solder the contacts to.

There are six miniature selector switches on this circuit board - four latched and two press-to-make. Two of these switches are shown below. Each switch is operated by a little button made of some kind of translucent plastic shit that fractures when you touch it (not a good quality in a button). Being custom-made to fit the Behringer console, these were not replaceable items (Maplin had never seen the like) and so we shored them up with glue from a hot-glue-gun. They won't fracture again, and they still transmit light from the indicator LEDs on the board. Bless the inventor of the hot-glue-gun. Get yours now and you will never regret it. A million uses.

The electronics sorted, the final step was to put the amp back together again. Below we are applying eff-off double-sided adhesive tape to secure the brown vinyl covering and to hide all evidence of our Great Hairy Leader's aggressive jigsaw-assisted entry. What you can't see in this pic is the wonderful new internal bracing behind the access panel, which is made of the finest seasoned Spanish oak, courtesy of Actreo Hardwoods (thanks Adam).



Rear view below. All done. You'd never guess we'd been in there, would you?

The moment of truth! We plugged it in and hired a crazy fiddler to take it through its paces. Sounds as good as new but we know it is technically sounder...

And finally - never a silver lining without diamonds falling out of his bum, our Great Hairy Leader made a beautiful bread board from the leftover Spanish oak.

Modding the Behringer - episode one

"Apart from that, how did you like the show, Mrs Lincoln?"

No. Our first project in 2011 concerns the Behringer - our Great Hairy Leader's acoustic amplifier, not the Derringer (Booth's notorious weapon of choice).

People in the music world will recognise Behringer as the German manufacturer of a range of rather nice sounding kit, well priced but with a reputation for questionable build-quality. Although not heavily gigged, our Great Hairy Leader's Behringer amp was beginning to show signs of wear - busted buttons and sockets, etc. The Secret Laboratory agreed to assist with repairs.

Opening the Behringer uncovered a host of manufacturing peccadillos, the first being that none of the abundant case-screws appeared to serve any structural purpose. After removing all screws, the interior of the case remained resolutely inaccessible. It might as well have been carved from a single block of MDF. It became clear that gaining access would require more than just a screwdriver.

Above, our Great Hairy Leader gains entry to the Behringer using an electric jigsaw. The rather festive little circles in the photograph are due to the sawdust storm he raised in my living room, each particle caught in the flash.

The case thus breached, it was possible to remove all of the gubbins that needed attention.

Above, our Great Hairy Leader discovers the problem. Everything is made of crap.

We had to break there to order new components online and steady our nerves with a flagon of cider. Remember to tune in to the next thrilling episode of "Modding the Behringer" later this month.

New recruit

Hello Lab fans. Please join me in welcoming our new associate, the erudite and alternatively-hinged Kate Mawby. We're all looking forward to seeing some of her projects documented here in the coming year.

Recycling

Reasons for never getting rid of that old Singer: However "new" a man you think you are, you will never be able to sew as well as your Mum without mechanical assistance.

Spectacles case. Media: Old fag-damaged fleece jumper.

Triboluminescence of sugar

Hello again. I've been really lazy recently. Well, not really lazy - I've been busy doing other stuff for other people, so I've neglected the Secret Laboratory recently. I don't even have a project for this month yet. I'm going to have to come up with something...

Anyway, just to fill the gap, I thought I'd introduce you all to a really easy technique for observing the phenomenon known as triboluminescence. Yes, this is my own method, I didn't nick it from the Internet.

Triboluminescence is an optical phenomenon whereby light is generated when chemical bonds are broken. So how do we do that then? Here we go...

Go out and buy a packet of generic "Extra Strong Mints". You know the kind I mean. They're hard, white and about an inch in diameter. Make sure they're fresh and dry - this doesn't work with soggy old mints.

Bear with me here. Take your mints to bed. Make sure everything is really dark. Hide under the duvet to make sure it's really dark. I don't mean just fairly dim, I'm talking pitch black, the kind of dark I imagine must have existed before the Universe was born. The kind of dark that doesn't even have space attached to it.

Stay in the dark for five minutes or more, keeping your eyes open. Your eyes will struggle to accommodate the dark but they will fail because it's really dark, right? You now have super-sensitive eyes, ready to detect the merest stray photon.

Take a mint from the packet and hold it 'twixt both forefingers and thumbs. Stare wide-eyed at the point where you judge the mint to be (you can't actually see the mint because it's really dark, right?)

Keep your eyes on the judged location of the mint - this phenomenon is fleeting. Snap the mint in half smartly by rotating your hands outwards to bring the broken faces uppermost. In other words, you're snapping the mint towards you, not away from you.

Did you see the flash? What colour did you see?

That was triboluminescence of sugar, brought to you by The Secret Laboratory. You can eat the mint now. Sleep well.

Warning: Eating mints can cause tooth decay. Always brush your teeth before falling asleep after observing triboluminescence of sugar under a duvet at night.