Separate the copper shield wires into a bundle. I wonder that accelero-metric transducer as large as the buzzer piezo element you are using would be able to accurately reproduce the sound from a vibrating node that large. A soldering iron and solder cost under £10 or approx $10, not a big expense and you'll probably find yourself mending good earphones that broke at the jack from metal fatigue, a soldering iron saved an expensive computer headset multiple times as the wire kept getting pulled when I stood up if it was caught on something; you'll find that you end up mending items that you'd usually throw out and re-purchase, usually at a much higher price than the soldering iron and solder. While there at FRAP, I installed hundreds of units in acoustic guitars as well as many other stringed instruments and other vibrating surfaces. Ideal for one to one conversations or small groups, it's small and discreet. However, when i put the mic on the floor near my laptop and play music out of it, I can hear that music from the mic signal. Typically the 10K resistor within the microphone's positive port offers this specific vital voltage for the procedure. Going to make a few of these, if only for the fun of it :). It might be more cost effective to purchase an inexpensive pre-made device. First of all thanks for the instructable, it really did help! When I connected it to a 12 foot guitar cable I got a lot of buzzing. Also brings back many memories of when I was an engineer at FRAP (Flat Response Audio Pickups), back in the early eighties. The way you have it set up, it's not actually doing balanced audio - for that you need the shield grounded, and the two inner conductors carrying mirror-image signals of each other which get subtracted from each other at the receiving end, thereby cancelling out interference. i count 30 ish on that rack :D, Nice job. Internal installations then exited through a machined jack that acted as the bottom strap end pin as well as an 1/8" jack (to keep capacitance down, like the choice of cable as previously mentioned. Replacement foam microphone … 3 years ago, Answer If the jack came with a plastic jacket, slide that over the shrunk tubing. Many online suppliers (DigiKey, Mouser, etc.) Product Description This throat microphone is for use with our personal voice amplifier. Battery Powered Lamp That Turns on Through the Use of Magnets! Hold the end of the ground lead on the solder blob and touch the lead and the blob with the soldering iron until the solder melts and forms a joint. This is to prevent any stray fringe wires ends from the copper shield from touching the the crystal contact when we solder the leads in place. Labernache, thanks much for the helpful comment! Throat mics are easy enough - eBay and mil surplus: aviation and army headsets appear in throat mic varieties (although Larkspur is getting a bit long in the tooth) and these generally work better than DIY. Solder the signal lead to the crystal terminal. But if your goal is to amplify an acoustic instrument like a guitar or especially something lower like a cello or bass, as you said, you should add a preamp with a very high input impedance, around 10 Mohms. If you are still looking for a solution, I am more than happy to help you by suggesting links to circuits and enough information for you to produce this item on your own. Shield and ground together or trim shield on both ends? It is powered by a small battery pack and can easily be plugged into your wireless transmitter/receiver. Bend the stripped end of the signal wire 90 degrees, to create a little tab that we will insert into the signal terminal of the jack. Random google hit with more info http://www.aviom.com/blog/balanced-vs-unbalanced/. As a DIY'r cost usually is not the most important factor when producing a product like the one you are requesting. Haven't tried it but interesting idea! Bragging rights reign supreme. I use these for broadcast quality radio interviews and have had very good success. Have you done any experiments using a smaller element and a preamplifier (like a FET type circuit to supply the necessary signal level as well as the required high impedance supplied to the source)? The President and founder of the company had a recording he made one very late night, of the suspension cables on the Golden Gate Bridge, being struck with a rubber mallet! I bought a cheap (10$) throat microphone that comes with a builtin preamp for mobile phone (meaning that you connect it to 1/8″ and I think the phone is sending around 2V to power to preamp). Also I wonder if there is a substance to go over the bottom of the piezo that will allow maximum response against the skin or if I should leave the bottom metal part as it is? It would seem to me that the smaller the pickup area, the better the chance of picking up only the hottest reinforced vibration node on the affected surface. Carefully strip around a half inch of the plastic or rubber cable housing from one end using a sharp hobby knife or an adjustable wire stripper. Hi! Worn around the neck, it is designed to help you reduce voice strain and improve intelligibility. The element is omni-directional and will pickup sound from every angle which makes it ideal for use as a throat mic. If there is filler, snip it off (be careful not to cut the wires!). My guess is that you'd get some interesting sounds from scratching, pecking, and movement, but wouldn't hear much from singing, other than what is picked up as vibrations in the window. Donald Bell. We made 55 of them (50 + 5 spares) in 2 batches for Glenn Kotche's "Prepared Drumhead Orchestra".