VU Perc Relay kit assembling

last update: 22 Jun 2022

VU Perc Relay kits assembling instructions.

(The SMT power connector you have to solder yourself the rest of the SMT parts are already soldered onto the PCB).

Needed:
• Metal cutting scissors.
• 1 second glue.
• Metal file.
• Hex nut drivers for the nuts.
• Philips head scre driver.
• Soldering iron (a nice one).
• Good skills to build things, it is not an easy kit.

All components in the kit.

File clean the relay on the side and the metal side of the piezo. so the have good connection when you glue them with the 1 second glue.

• Solder the thinnest of the sheet copper to the side of the piezo for extra reverb.
• There are 5 legs on the relay, cut 3 of as show on the picture. The legs that are cur of ar the legs to the switch of the relay. The legs to the coil of the relay should be NOT cut off. After cutting them of you can also file them off a bit more so the surface is flat and sticks good to the tape.
• Stick it to the double sided tape on the PCB.
• Wire up the Piezo to the PCB. color does not matter just where the wire goes.
• When soldering the Piezo element, solder verry shortly, and not to hot otherwise the element will burn up.

• Put in the small components.
• ATTENTION 2 The LED's have orientation to one side, the other 1 LED has orientation to the other side. Check the image for the flat side of the LED, or check the PCB where it is written where the short pin goes.
• Put in all resistors.
• The trim pot is 5k
• Put in the 2x3 male header connector (i forgot to add it in this picture (if you are not sure what side it goes on check images below where i have soldered it on already).

Cut the VU Meter on the corners where i cut it to and wiggle with the cutters to get it loose.

• Cut the sides of the piezo, be carefull not to damage the piezo element. i use metal cutting scissors that look like normal paper cutters, they are the best, no idea where to buy them.
• use a big cutter to snap on the sides of the VU Meter.
• Stick it to the sticky tape.
• You can give it extra strength by drillin 2x 1mm holes thru the vu meter and solder a wire to the corner of the piezo. i did not do this on the pictures. but it can help to be sure it will never come off. when you start soldering the sticky tape glue becomes soft and it can fall off but it can be stuck on again easily.

Solder one of the LED legs to the side of the Piezo and bend it like the above picture. Then cut the thin shrink tube in two and shrink one half on. Then put the other over the previous one and shrink it over that one.

Bend the bigger copper strip and add it like the above picture. Then add the bigger shrink tube on the end where the uu meter hits it.

Solder the wires as above and if you want to you add extra reverberation with left over copper strips.

• You can also add a little resistor leg as a little ring to the reverberation spring this will give a nice ratle effect to the sound.
• Make sure there is enough distance between the left hitter and the right hitter, the vu meter will center when the module is powered on and it needs space to move.
• Spray paint the piezo's to prevent oxidisation.

Now it should look like this (as you might see i forgot the 2x3 connector so i added it at the end).

• Solder the SMT power connector to the PCB.
• Then add the 100k (marked 104) the top left corner, and 200k (marked 204) trim pot in the middle at 45 degrees.
• Solder the push buttons, they have polarity, check PCB silkscreen for the line and the line on the switch.

Solder the Vactrol (GL5528 + ultra bright red LED) the light does not go in because the shrink tube bends as you can see. The side with short and long leg is the LED, see pictures where it goes, it is also written the silkscreen.

One 22pf capacitor is added over the 200k trimmer pot.

• Put in the 10nf (103) capacitor and the 15k and 22k resistors (do not solder them yet).
• Put in all components dont solder them befor mounting them to the top panel.
• Solder everything.

I use two planks to push in the IDC connector.

Make cable as below. and push it onto the module with the VU Meter and Relay. connect the side that is the lowest otherwise it does not fit (see pictures below).

For the IDC power cable copy a cable you already have, power connection polarity is marked on the PCB.

• Cut if two of the rubbers to make washers out of them (two not all).
• Add as picture below.
• Now mound the sound module withe M3 nots

Finished ;) .. not yet. now you need to tune it.

• Check for short circuit before powering on.
• The 100k trimmer is used to center the VU Meter.
• The 200k trimmer sets the gain, there is a soft clipping circuit try to keep the volume below it a bit so it just cuts of spikes.
• Make sure the copper metal parts (springy parts) can move freely and are not touching wires or the PCB.
• Thats about it, have fun with it!
• p.s. add knobs.