Control LEDs with Audio signal

Hello everyone! I would like to control an LED strip (This 12v one:

by using the output of this microphone module:

By control I mean the voltage out of the microphone module to control the voltage in (brightness) of the single channel LED strip.

Because of my inexperience and lack of info on the page, I cannot tell if that mic module output has a DC bias, etc (hopefully you have an idea?).

So I have been researching, but again because of my lack of experience it is hard to tell what direction to go. I would like to do this WITHOUT an Arduino and with a circuit alone! I assume I should use a transistor, I was thinking a MOSFET but can't get it to work :/

So my real questions are: What kind of transistor/component should I use for these (mic and LED strip)? What other values of components may I need to get for it to work? (Resistors, Capacitors, diodes, amplifier?) Also if you had additional advice on what kind of potentiometer I should get to attenuate the voltage feeding into the LED strip so I can tweak the range?

I hope this makes sense and I really appreciate any help or guidance! Thank you

Hi, Have you googled sound reactive led strip arduino


sound reactive led

Tom... :)

Hey Tom,

Thanks for the advice. However, in my post I said I would like to do this without arduino (even though this is the arduino forum :p) Hence the difficulty for me (would be a lot easier with Arduino for me, but I have to make many of these spread out long distances)

*edit Ok I guess your answer edited without Arduino. I will take another google search in the way you recommended :)

ndivuyo: By control I mean the voltage out of the microphone module to control the voltage in (brightness) of the single channel LED strip.

Wrong microphone module. That one only has a digital output (on/off).

For brightness control you need a 4-pin mic module (with digital and analogue output). And the analogue value needs to be converted to PWM for the mosfet. Something you can't do without an Arduino. Leo..

Thanks Wawa!

Ok so lets say I acquire a module that has analogue output. These links suggest solutions with TiP31:

The bottom link has other suggestions and versions of circuits including people suggesting to use TiP121

Any comments/validation of these solutions especially in respect to Tip31 vs 121 solutions?

I additionally have many of these amplifier modules if useful:


Those links show crude solutions. Make sure you have a bunch of spares if you want to go that road. Leo..

I see, so a correct solution I assume will take many more components? It is for a one day installation so crude isn’t terrible… maybe I will have to rethink if there isn’t an effective simple solution

In general you have to get a microphone and amplifier (module), that can drive a transistor. The transistor must be strong enough for driving your load. The required information is not normally available from Amazon or Ebay offers, so nobody can help you with such items. You should look for products with data sheets first, from serious providers.

The amplifier must extract the volume (envelope) from the microphone signal. A digital module has means (a pot) to set the sound level where the output signal changes from low to high. If you want more than an on/off blinking LED strip, you need an analog module.

The transistor and your power supply must support the maximum current of the load (LED strip), and the amplification of the transistor must be high enough to reach the full current at full input.

If you use PWM to drive the transistor, it may work without a heat sink, but driven by an analog signal a big heat sink (and fan?) will be required to prevent the transistor from burning down. You can go the easy way by adding an Arduino for the PWM signal generation, or the hard analog way.

A transistor requires some offset (bias, threshold...) voltage before it turns on. If the output level of your amplifier is not high enough to exceed that bias, you have to add e.g. a feedback resistor that turns the strip halfway on, then add the amplifier output to make the strip shine brighter or dimmer.

Finally get a voltage regulator that produces the operating voltage of the microphone amplifier from the LED strip supply.

Do you understand now why even detailed pictures do not reveal all that required information, and data sheets are required for every single item?