![]() ![]() ![]() I need to take more pictures to correctly illustrate this. This stuff is a bit tricky and care needs to be taken not to set up any ground loops. Another subject worth exploring is shielding the leads by wrapping copper foil around the wires and grounding back to the ground lug. Parallel has a very desirable reduction in impedance. Series doubles the impedance and parallel halves it. Basically they are wired in parallel so that each set of leads goes back to the jack - so it would be a pair of reds and a pair of blacks coming back to the jack to use double piezos. ![]() When I get time I will put together another blog to illustrate how to double these piezos up reduce the impedance to closer to what a standard amp wants to see. I have not had good luck keeping these tight enough yet and intend to use gel super glue liberally on the next installs to see if that will help. ![]() Mounting the jack to the box typically makes me drill two holes - a larger one half way thru the box then a smaller one all the way thru. The foam mounting tape is double sided "Duck" brand 3/4 inch by 22 ft and 1.5 inches holds a quarter pound. This makes a nice clean installation and its extremely strong. I mount mine to the neck as it goes thru the box close to the bridge - I use foam mounting tape that sticks the brass side of the piezo to the neck - I use two pieces side by side to get it wide enough and then cover the top with two more pieces side by side to cover and buffer the piezo. Its not necessary to add wire to the ones I have built nor to put any switches in the circuit. If the wire and terminal are hot enough the solder wicks up the wire as it melts - nice smooth and strong. You do NOT melt the solder and drip it onto the wire or terminal. If the joint is not hot enough you will get a cold solder connection which is BAD. If its done correctly it will all be silvery smooth and fairly quick. The tip heats up the parts to be soldered and then the solder "runs" up the wire and into the joint. Stick the tip in the hole on the jack and wait a few seconds then touch the solder to the tip where it came thru the hole and or to the wire itself. Tin the tip by melting a small amount of solder on it. Once twisted up tight plug the iron in and let it heat for ten or fifteen minutes. Insert it in the jack and twist it up tight so there is a half decent mechanical connection black goes to the center ring ground terminal on the jack and red goes to the lug that leads to the tall center pin part. Now you can strip the insulation off the wire back a bit and twist the the strands into a single smooth wire. DO NOT BREAK IT by applying to much pressure. The piezo will pop right out with very light pressure. Then stick a blunt small screw driver in the hole in the bottom of the case and gently push up. Careful the Piezo is suspended in there but its close to the top. I insert a pocket knife tip or small screwdriver in and slide it right under the plastic top so it misses the piezo completely - then pry the top up and it will pop right off. You have two ears so two chances to get a good hole in the box to pry the top off with. I take a pair of pliers and grasp the ear on one side of the case -squeeze and snap the ear and a piece of case off. I have put together a picture story line to illustrate this. Since we want it to pickup the sound from our guitar and send it to our amplifier it needs to come out of the case. The 273-073 piezo comes suspended in a plastic case as its original purpose is to be a buzzer. (11$ at Radio Shack) and also save considerable on the solder and soldering iron. If you go to Harbor Freight you can pickup a "helping hand" for only four bucks. (just a small fan blowing across you will do the trick) Speaking of stink, ventilation is good as the fumes are not very healthy to breathe. Too big an iron will burn the insulation off and melt plastic not to mention stink. This is normal for a low watt iron and you certainly don't need more watts. It might take it ten or more minutes to come up to temp. (common mistake) Give the iron lots of time to heat up. Do not remove these screws and pull as it will junk the iron. Do NOT tighten up the little screws on the barrel too tight as they hold the heating element in. Keep it tinned (heat the tip and run some solder on it before soldering) Cheaper and easier to wear out a cheap iron and replace unless you're going into business. If you use a damp paper towel or sponge and keep the soldering iron tip clean it will last a fairly long time. #274-255 and are two for 4 You can also pickup a 25 or 30 watt soldering iron and some fine(thin) rosin core solder here or go to Harbor freight and save some money. They are in a drawer case towards the back of the store and most stores usually have them in stock. A trip to Radio Shack will get you the piezo and 1/4 inch mono jack. ![]()
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