Wire Pickups & Preamps
Lamb has been working with the wires for the past 30 years. During this time he developed a low cost technique of attaching ‘piezo’ stereo contact microphones (pickups) to make field recordings and listen to The Wires. The piezo pickups require a preamp and Lamb has been using the Fishman Powerjack miniature endpin’s which offer great fidelity and ultra-low power consumption. These recordings expose an infinite and amplified universe of sound that sonically reflects things we cannot see. The Wires sonically reproduce environmental and human interactions with an enormous dynamic range of harmonics and frequencies. Whilst having traditional sonic qualities such as pitch, timbre, rhythm and key, the sounds produced are perhaps best described as a deep space atmosphere with earth hums and electro-pings, even insects can be heard as they collide or crawl up and down the wire.
There are a number of alternative methods in use. The following is an informal description of the process Alan Lamb first demonstrated at WIRED Lab, and serves as useful starting point for experimentation.
Piezoelectric Bimorph Element converts mechanical vibration into electrical signal (RS Part Number 285-784) costs around $5.00.
Attached to wire by double sided tape
Solder connections are encased in waterproof sealant such as Selleys All Clear Multipurpose Co-Polymer sealant, which is commonly used for sealing bathrooms and roofs.
Piezo pickup tip is glued to the wire. We use Selleys Kwik Grip contact adhesive.
Best position away from the poles, preferably at least a few metres. Choose your location carefully. We aim for about +/- 45 degrees from vertical and as much horizontal separation as possible, at least open arms length.
Depending on location the Wire may have to be earthed, and sometimes this earth needs connecting to recording devices earth too. We often earth centrally between the Pickups.
PIEZO PICKUPS PHOTOVIEW
This series of pictures are an informal quick look at the main piezo pickup construction method we’ve been using for the last year or so. We’re always fiddling and altering the way we do this, experimentation is part of the process.
The pickups are soldered up to their cables in the workshop first and transferred to the wire site in protective boxes.
Note that in this series of images the attachment method is slightly different to that in the image shown at the top of this post. Instead of glueing the pickup to the wire, double sided tape is applied as a base for the piezo pickup.
The entire piezo element is then wrapped in double sided tape.
If necessary cable ties can be used to make a tighter grip, but care must be taken not to break the piezo element!
Entire pickups are encased in waterproof sealant such as Selleys All Clear Multipurpose Co-Polymer sealant. Sometimes they can get quite gloopy and big depending how much sealant is used. Spiders love these blobs and move in pretty quickly, great for bioacoustics.
Note the cabletie holding the audio lead to the wire, this is important while the sealant sets, but can be removed later if required.
Note the earth lead for keeping down those nasty powerline hums.
Very quick and simple method, can be fixed or moveable. They are easily attainable and can be sourced from a cheap second-hand electric guitar. We’ve used found guitar pickups as well as new ones.
Piezo pickups require a very high impedance preamp, and because we are also field recording we need to have long battery life. Alan’s preamp for many years is the Fishman Powerjack miniature endpin preamp. These preamps are designed for piezo pickups on acoustic guitars.
Runs off a standard 9 Volt battery.
Ultra low power and has a battery life of 12,000 hours!
Appear to work pretty well in a wide operating temperature range.