Magnetic Piezo Contact Microphone & Preamp

Global Blackouts happen in Ukraine from November 2022 till Marth 2023 from the ruzzian missile attacks ..

At that time period, we have a lot of experience in saving electricity .. Many people (and me too) made DIY power stations and other stuff to have light, internet, and other bases things in a time when general electrical lines were broken ..

Before that time I have no experience with rechargeable devices with batteries .. But .. I have a lot of experience with a contact mic because I use it in my live sound performances ..

A time ago I have made a few same things and all the time has some problem with the signal transferred .. All the time I have a problem with the signal because the pure signal from piezo is very light and it was loosed on a way by cable to the amplifier from the sensor ..

At the same time, my friend, modern Ukranian composer Yana Shlyabanska who moved in evacuation to France want to create a project that used contact microphones and ask me for some solutions .. We have to spend time finding something (cheap and simple) that works well for her project ..

But it is nothing ..

It is not a big problem for me, because I play experimental expressive industrial sounds and some kind of noise in the process of it only has "Worse is better", but that problem, I mean the problem with a loosed sound from the sensor has existed and then Yana asked me about piezoelectric sensors and we made research, I say that I think we need put a preamp at the signal start ..

So ..

I have found:

• Battery [ 3.7V 400mAh 582728 LiPo ],
• USB charger module with protection,
• Microphone amplifier module [ works in the range of 3 ~ 12 Volts ],
• Neodymium magnet [ ring ],
• Piezoelectric sounder sensor,
• On\Off switch button,
• Epoxy glue [ two-component ],
• Silicone glue [ rods ],
• Connectors and some different wires.

Instruments:

• Soldering iron,
• Hot glue gun,
• Side cutters,
• Cutter knife,
• Lighter.

✶ ✶ ✶

Supplies to Ukraine are limited due to the sea blockade of ports, and railway communication is difficult .. I found products on the local marketplace and they can be slightly different from the links that go to similar products on Aliexpress ..

✶ To control the battery charge, it is necessary to use a special device to ensure that the battery is not overcharged, anti-short circuit, or other trouble..

✶ Remove the microphone from the circuit and connect it to the battery charge circuit ..

✶ Also, I added a small on/off button to control the power supply ..

✶ Prepared and connected the neodymium magnet and piezoelectric sensor by the two-component epoxy glue each other and with the battery ..

✶ In the finale, make a plastic cover with silicone glue ..

Every sound artist who has worked in their own practice with contact microphones (built on the basis of piezo sensors) has faced the fact that the signal from the sensor needs to be amplified ..

The remoteness of the sensor from the amplifier creates additional difficulties, since the signal is 'lost' on the way to the amplifier due to resistance, plus all kinds of pickups, and as a result either the signal is not sufficiently clean or it is necessary to place the sensor as close as possible ..

This simple solution should help, since the signal goes directly to the pre-amplifier and, already minimally amplified, can be transmitted over a fairly large distance .. I have tested it with a cable 10m in length and the sounds from the sensor are perfect and ..

It should be noted that as a result of the research, some interesting applications of a similar plan presented on the market were identified, but they were too expensive and did not meet our requirements as a magnet, or those size, or workmanship ..

Including, for this reason, we find (I hope) an interesting solution ~ it looks very simple, but all simple things are magic .!

✶ ✶ ✶

I want to say Thanks to the person who inspired me, my friend, Yana Shliabanska ..

In collaboration with Yana, we have made a few interesting sound works, and that is a small part of the support that I can take to her .. Hope those small and simple devices have been helpful to her live performances in the Future ~

Yana is a modern Ukrainian composer who works with electroacoustic sound, and she is also now taking part in a volunteer movement Me For U (Medicine For Ukraine) which collects medicine support for Ukrainians who fight now with ruzzian occupants ..

The intensity of the fighting is such that volunteers take on a significant part of the supply of the Armed Forces of Ukraine .. We all try to help in some way to bring Victory closer ~ ~

💙💛

Glory to the Heroes and Victory to Ukraine .!