Here is a proper studio hack in which YouTuber Ryan Mobitz shows how to produce, not one, but two different lo-fi mics using an old telephone handset with a carbon microphone.

You will need some electronics and soldering experience to undertake this hack or know someone who does.

Ryan starts by dismantling the handset and set aside the carbon mic and the earpiece, which he uses as a dynamic mic.

Next, he gives the handset a respray, to turn it bright red. This is of course optional and will have no impact on the sound.

What you will need in addition to the phone handset a DP/DT switch (double pole/double throw) so you can switch between the 2 mics. Then to power the carbon mic from 48V phantom power you will need the following…

• A 6k8 (6.8K) ohm resistor

• 1uF capacitor rated at 50v or more

• 600:600 audio transformer with at least one of the windings having a centre tap

Then finally to be able to connect this lo-fi on a mic preamp, you will need a lead with a male XLR on one end.

Here is the wiring diagram…

Once you have wired the handset up then Ryan suggests using some gauze to stop the transformer from rattling as well as a circle of gauze over each of the microphones to serve as a pop filter.

Once completed the switch determines which mic you are using and remember to enable phantom power when using the carbon mic.

Then at 3:20 into the video Ryan plays some audio examples that were played out through his studio monitors to give a sense of the different sounds of the 2 mics.

The earpiece, now a dynamic mic gives an instant radio-effect sound whilst the carbon mic has an improved bandwidth, but with a higher noise floor and definitely sounds gritty and dirty.