In this Instructable you will be making an Audio Transformer System made from recycled transformers.

The advantages of this circuit are:

- electrical isolation (if two ground outputs are not connected there could be a chance of spark or short circuit),

- different loudness and frequency responses for each of the five transformers.

Supplies

components: solder, do not use the multiple numbers of switches, especially for outputs incase you turn more than one switch ON at the same time, use two rotary switches (SPMT - Single Pole Multiple Throw), transformers (at least two), wires, box (plastic/cardboard), electrical tape, blue tack.

tools: soldering iron, wire stripper, screwdriver, pliers, scissors.

optional components: matrix board.

optional tools: USB oscilloscope, multimeter, coil meter, voltmeter.

Step 1: Design the Circuit

This circuit has no short circuit protection for output. I could have used resistors. However, that would mean power loss.

This circuit is showing only three transformers. I used five. However, you get the idea.

Step 2: Build the Circuit

You need to ensure that all transformers are secured to the box with plasticine, blue tag, bolts/nuts or cable ties. Otherwise, there is a high chance of a short circuit that will damage your audio output.

Each rotary switch should have only one input/output (orange wire at the centre of each switch). For the first switch, the orange wire is the input, for the second switch, the orange wire is output.

Use electrical tape to cover all contacts to prevent short circuits that might damage your audio output.

I used a blue tack that might not be a professional way to attach the components to the box. Also, a cheap blue tack might not stick well. You might need to purchase the original brand.

You can also use 1 mm metal coil to attach components to the box. The coil is insulated and will not cause short circuits, unlike metal wire.

Step 3: Test the Circuit

You can hear that the sound characteristics do not vary much. You can try different types of transformers. Unfortunately, all of my five transformers had similar frequency responses and transfer characteristics (2-dimensional graph/plot where the system input is X, the system output is Y). There are non-linear transformers that can try using to obtain different sound characteristics.