EM-Tronic Synth




Introduction: EM-Tronic Synth

About: Brian McNamara is an experimental instrument builder and sound sculpture artist based in Bungendore, NSW, Australia. Brian mixes his passions for music, electronics and sculpture into unique objects that shou…
In this Instructable I will show you how to build a small handheld digital synth called the EM-Tronic.

About the EM-Tronic:
With the combination of pitch, speed and mode controls, giving endless combination of sounds this Synthesizer packs quite a punch for it's size. The best thing is I've included the basic software file so you can hack the sound to your hearts content.

The information in this Instructable is all you need to build this synth but if you would just like a kit to put together I have made a few up. EM-Tronic KIT

You will need:
*Circuit board ( get one made or just use strip board)
*The ability to program a Picaxe 08m2 Microcontroller.
*Electronic components( resistors, capacitors, voltage regulator, 9v battery clip, switch, potentiometers, 3.5mm socket, knobs,Picaxe 08m and LEDs
*Soldering iron and solder
*Wire cutters
*Allen key to fit the knobs
*An enclosure to fit the kit into if you want one.

Apart from these instructions I've included the circuit board schematic(eagle), circuit board layout(eagle) and the software file EM-tronic.BAS. This gives you all the details you need to build your own EM-Tronic. If the files don't download or I've left something out please let me know and I will sort it out.

Step 1: Parts

1 x 100nF Capacitor (C5)
1x 10nF Capacitor (C6)
2x 10k Pot(spline shaft) (VR1 VR2)
4x 10K Resistor (1/4W) (R2 R4 R6 R7)
2x 1K Resistor (1/4W) (R8 R10)
1x Regulator 78L05 (5V) (IC3)
1x Ic Holder 8Pin
1x Picaxe 08M or 08M2 (IC2)
1x 3.5mm Socket(stereo switched) (SPKR)
1x Toggle switch(sub miniature)
2x Knob
1x Battery connector(9v)
1x Circuit board

If you don't have a picaxe programmer or programming cable try SPARKFUN

Step 2: Fit the Components Part A

In this step we fit the resistors, ic socket, audio jack, capacitors and voltage regulator.

*Solder the 2 1K(R8 R10) and the 4 10K(R2 R4 R6 R7) resistors to the PCB.
*Solder the 8pin IC socket to the PCB in the IC2 position.
*Solder the 3.5mm audio connector to the PCB in the SPKR position.
*Solder the capacitors 100nF(C5) 10nF(C6) to the PCB.
*Solder the voltage regulator(IC3) to the PCB.

Step 3: Fit the Components Part B

In this step we will be fitting the LEDs, switch, battery connector, potentiometers and Picaxe 08M.

*Solder the LEDs to the LED1 and LED2 position on the PCB. Note: the the long lead of the LED is positive.
*Solder the 9v battery connector to the pads marked PWR, red to + and black to -.
*Solder the switch the S2 postition on the PCB. Note: you may need to enlarge the holes a little to fit the switch.
*Solder the 2 potentiometers(10k) to R1 and R2 on the PCB.
*Using your Picaxe programmer and programming cable program the O8M with the EM-Tronic.Bas file.(This step is only if you don't have a pre-programmed picaxe)
*Fit the programmed Picaxe 08M to the ic socket on the PCB. Note: the 08M and 08M2 parts are interchangeable.

Step 4: Fit the Knobs

Using an allen key fit the knobs to the potentiometers.

Step 5: How to Play the EM-Tronic

Your now ready to play, fit a 9 volt battery, plug in some earphones or an amp and have a play.

How to play the Em-Tronic
Main controls:
Pitch: the pitch control allows you to make, 127 tones and 127 white noise variations.(right potentiometer)

Speed: The speed control has different functions depending on what mode is set, but essentially, it sets the time a tone or tones are played and repeated.(left potentiometer)

Mode: the EM-Tronic has three modes, mode 1 is basic and gives a bleep at the pitch and duration you set. mode 2 is delay mode, this mode gives a delay effect as you move the pitch control up and down. Mode three includes a delay and multiple notes played rapidly.

The output is via a 3.5mm stereo socket which can be plugged into earphones, a computer sound card, mixer or amplifier.

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    8 years ago on Introduction

    Can you please post a photo with the positive + side?


    10 years ago on Introduction

    I built it and it is awesome...really the schematic is the same for all your synths and so I just programmed other chips and alternately plug them in alternately. It is really fun...LOTS of sounds.


    Reply 10 years ago on Introduction

    No, it's plugged directly into my little Vox amp.


    10 years ago on Introduction

    Cheers rarebeasts, I though this was going to be an ab nightmare but it turns out is pretty easy going, having said that the proof will be in the pudding when ive got my soldering iron all fired up :) epimediumhorny goat weed reviews