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If you like lights and music, you’ll have fun building this LED Color Organ. You plug your music into it, and the circuit divides the sound into high, mid, and low frequencies and then flashes 3 different colors of LEDs according to those frequencies. Blinky!

When Collin Cunningham published his fancy LED Color Organ in MAKE’s Circuit Skills video series, one reader was inspired to build a simpler circuit to achieve the same goal. Akimitsu Sadoi designed this bare-bones version that works great and uses only about 30 components. You can find the schematic right here and build it on a breadboard with no soldering required!

Assembly is broken into 4 parts:

  • The audio input — the circuitry that takes the signal from the audio jack.
  • High frequency — blinks the blue LEDs when high-frequency tones play.
  • Mid frequency — blinks the green LEDs when mid-frequency tones play.
  • Low frequency — blinks the red LEDs when low-frequency tones play.

Photo-Jun-18,-11-10-32-AM

Steps

Step #1: Jumper the power and ground rails.

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  • Install jumpers as shown, to provide power and ground all across the breadboard.
  • Install the 9V battery connector. Red to red, blue to black.

Step #2: Connect the audio jack.

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  • Insert a 10kΩ resistor (brown, black, orange) from the power rail of the breadboard to an arbitrary row. Remember, resistors aren't polarized, so it doesn't matter what orientation it's inserted in.
  • Insert the 2N3904 transistor (it should have a small "3904" labeled on the front) into the breadboard, with the flat side facing toward the breadboard’s central “trough”. Looking at it in this orientation, the left leg is called the "emitter," the middle leg the "base," and the right leg the "collector."
  • Connect the negative column to the leftmost pin of the transistor, the emitter, with a jumper.

Step #3:

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  • Connect a 1kΩ resistor (brown, black, red) from the power rail to the rightmost pin of the transistor.
  • Wire the second 10kΩ resistor from the one you installed earlier to the base of the transistor.
  • Connect the diode from the row with the two 10kΩ resistors to the leftmost pin of the transistor, noting the polarity (the black stripe of the diode should be nearest the transistor).

Step #4:

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  • Connect the 10µF capacitor from the base of the transistor to the other side of the breadboard, again noting the polarity: the positive side, without the black stripe, should be connected to the transistor.
  • Connect two 100Ω resistors (brown, black, brown) to the negative leg of the capacitor and insert their other legs into 2 separate rows. This is where the left and right audio inputs will connect.
  • Use alligator clips to attach jumper wires to the 3 legs of the audio jack, or solder them on directly, as I did here. The one sticking out the bottom of the jack is ground, and should go to the ground rail on the breadboard. The other 2 pins are for the left and right audio inputs, and should each be connected to one of the 100Ω resistors we installed earlier (it doesn't matter which).

Step #5: Build the high frequency filter.

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  • Insert a 2N3906 transistor into the breadboard (flat side facing forward, again).
  • Connect power to the emitter leg (the left one) with a jumper.
  • Connect power to the base of the transistor with a 2.2kΩ (red, red, red) resistor.

Step #6:

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  • Insert the 0.047µF cap into the board, connecting one leg to the base of the transistor and the other to an arbitrary spot on the other side of the breadboard, over the trough.
  • Connect the other leg of the capacitor to the collector of the 2N3904 transistor with a jumper wire.

Step #7:

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  • Connect the positive leg of a blue LED (usually the longer leg) to the collector of the transistor.
  • Hook up a 100Ω resistor (brown, black, brown) from the negative leg of the LED (indicated by the flat spot on the LED casing) over the trough to the other side of the board.
  • Connect the positive leg of the second blue LED to the 100Ω resistor, and the negative leg to ground. You can insert the LED’s negative leg right into the ground rail or use a jumper.

Step #8: Build the mid frequency filter.

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  • Insert another 2N3906 transistor into the breadboard, with the flat side facing the trough again.
  • Connect the emitter of the transistor to the power rail with a jumper wire.
  • Connect the base of the transistor to the power rail of the breadboard with a 2.2kΩ resistor.

Step #9:

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  • Hook up the 0.01µF cap between the base and emitter legs of the transistor. Polarity doesn't matter with a ceramic capacitor.
  • Now connect the positive leg of the big 0.47µF cap to the base of the transistor, and the negative leg across the trough of the breadboard.
  • Connect a 1kΩ resistor (brown, black, red) from the negative leg of the 0.47µF cap to the "hub" — the positive leg of the second blue LED you installed earlier. This connects all parts of the circuit together so they can work together; you’ll connect other sub-circuits to this "hub" later on.

Step #10:

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  • Connect a green LED’s positive leg to the rightmost leg (collector) of the transistor.
  • Connect the 180Ω resistor (brown, grey, brown) from the negative leg of the LED across the trough.
  • Connect the positive leg of the remaining green LED to the 180Ω resistor, and the negative leg to ground.

Step #11: Build the low frequency filter.

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  • Insert a 2N3906 transistor into the breadboard, with the flat side facing the trough as usual.
  • Connect power to the emitter leg of the transistor with a jumper.
  • Connect a 2.2kΩ resistor from the power rail to the base of the transistor.

Step #12:

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  • Insert the 1µF cap into the board, with its negative leg connected to the base of the transistor and its positive leg connected to the emitter.
  • Connect another 2.2kΩ resistor across the trough of the breadboard, from the negative leg of the 1µF cap to an arbitrary spot on the board.
  • Connect this 2.2kΩ resistor back to the "hub" with a long jumper wire. This connects the low frequency sub-circuit to the rest.

Step #13:

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  • Insert a red LED into the breadboard, with its positive leg connected to the collector of the transistor.
  • Connect the negative leg of the LED, across the trough of the breadboard, with the 270Ω resistor (red, purple, brown).
  • Connect the positive leg of the remaining red LED to the 270Ω resistor, and the negative leg to ground.

Step #14: Now you are ready to rock!

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Plug one of the male ends of the audio splitter into the audio jack, and the other male end into your audio source (stereo, computer, etc.). Now plug your audio output (headphones, speakers) into the female end of the splitter, plug the 2 ends of the 9V battery clip into the ground and power rails of the breadboard, and start pumping the tunes!

Conclusion

Thanks to Akimitsu Sadoi for his original circuit, on Instructables.

Eric Weinhoffer

Eric is a Product Development Engineer at MAKE. He creates kits and sources products for sale in the Maker Shed, focusing primarily on manufacturing. Occasionally he writes about cool things for the blog and magazine.


Comments

  1. nathanael says:

    can you run this off 12v battery

  2. David W says:

    No schematic? That should be a mandatory part of any project post like this.

    1. Eric Weinhoffer says:

      It’s linked to in the description now! Also right here: http://www.instructables.com/files/orig/FKQ/ZKWQ/GQ5PYWHF/FKQZKWQGQ5PYWHF.pdf

  3. Lovji says:

    We need a schematic for this project. Thanks.

    1. Is there something missing near of 10k ohms resistor and first diode or is just a short?

      1. Eric Weinhoffer says:

        Hi Luis,

        Nope, that isn’t a short…the 10k resistor and diode are connected.

        I guess the correct way to show that in the schematic would be something like this: https://www.evernote.com/shard/s90/sh/4a3bf0f4-2732-415e-8144-f4d1857e886c/5cb7a2f73f32c85732cc7cd31cb16016/deep/0/www.instructables.com/files/orig/FKQ/ZKWQ/GQ5PYWHF/FKQZKWQGQ5PYWHF.pdf.png

        Hope that helps!

  4. Could an electret microphone be attached to this to view frequency of live voices instead of an mp3 player?

    1. Samalert says:

      Am also waiting for the same

      1. Eric Weinhoffer says:

        Theoretically, yes. I’m not sure how the wiring would change — you may need to add a few extra components to work with your microphone.

  5. catalin says:

    what voltage should the capacitors be ?

    1. Eric Weinhoffer says:

      For the electrolytic caps, I’d recommend 25V.

    2. Peter says:

      what if I used 50v elect. caps? – which is what I used
      as soon as I tap the 9v into the circuit, the leds will flicker. but then once fully connected the leds wont turn on at all.

  6. Ashray Malhotra says:

    How do I connect an audio player to the circuit? I understand the complete circuit except how to connect my phone/laptop to play the audio.

    1. Ashray Malhotra says:

      Basically how do you get the Left and right audio inputs from a music player.

      1. Eric Weinhoffer says:

        As described in the last step of the project, you’ll need an audio splitter (two male, one female). One of the male ends goes to your audio input (MP3 player, computer, etc.) and the other gets plugged into the audio jack on the board. The female end of the splitter is your output, so that gets plugged into your speakers. I hope that helps!

  7. Alex says:

    We made awesome modifies to the project!!!!

    1. make2013 says:

      I want to make this but am unsure what wattage to use. What did you all decide? Is there a way to know this without it being listed in a parts list? Thanks.

      1. Eric Weinhoffer says:

        1/4W parts should suffice.

  8. make2013 says:

    I want to make this but am unsure what wattage to use. What did you all decide? Is there a way to know this without it being listed in a parts list? Thanks

    1. Eric Weinhoffer says:

      1/4W Resistors should suffice.

  9. Virginia Phillips says:

    Hey out there – I’m a mom of a 10-year old electronics enthusiast! We are trying to do this project – looks easy to my son, but we (really I) need clarification on parts. For the Capacitor, 10uF electrolytic, we checked sparkfun.com and found https://www.sparkfun.com/products/523 It says it is 10uF/25V – is that what we need? I would ask my child but he’s asleep and we are trying to get all this stuff ordered. Thanks for your help! :)

    1. Eric Weinhoffer says:

      Yes, that will do the trick! The yellow stripe signifies the negative side in this case.

      1. Virginia Phillips says:

        Thank you!

  10. Samalert says:

    What more can be done to use a sensitivity thing(POT can be used but am electronic newbie). Also what more changes can be done if MIC is used than AUX and lastly but not the least LED strips are on hit so how can the same be implemented for LED strips

    1. Eric Weinhoffer says:

      Theoretically, a microphone could be used instead of the AUX jack, but that would probably require additional electronic components or, at the very least, different wiring. I’d recommend searching around on the web for that — try searching for “Microphone Color Organ”.

      I agree; it would be great if we could use this project with LED strips! The problem with those is you need to pass a digital signal to them to declare a color. They also require a lot more power than just two LEDs, so it would be quite difficult to get them working with this project.

      1. Samalert says:

        Yes but rather than using a RGB strip we can configure single color strip for each individual filters but what am not able to calculate is how much current to force in the circuit and make them glow bright. And now since we are pushing more current the values of components may change and which i am not aware of. And it would be tremendously great !

        1. Eric Weinhoffer says:

          That’s a good point – you could probably use one strip of a static color for each frequency band. I don’t know how much current is required…that completely depends on the strips you’re using. I’d recommend looking around online for other projects that are similar to what you’re looking for, like this: http://forum.arduino.cc/index.php?topic=115045.0

          It may be easiest to use an Arduino here, instead of building it analog with just components.

  11. Mike Ring says:

    We’ve followed the directions and double-checked the parts, but the low frequency filter is on constantly once we plug the battery in, and stays on when a source is connected. Any suggestions?

    1. Eric Weinhoffer says:

      Hi Mike! Have you tried turning the potentiometer to adjust the sensitivity of the filters? By dialing that down, more of an audio input will be required to light up the LEDs, and should keep the low frequency filter from staying on all the time.

      1. Mike Ring says:

        Where exactly is the potentiometer?

        1. Eric Weinhoffer says:

          Oops, sorry, there isn’t one! Was thinking of another project…

          What I’d recommend is triple-checking your polarity — inserting an LED the wrong way could easily cause it to stay on at all times. I’d also check your components to make sure you have the correct values and ensure that none of them are burnt out — incorrect (or slightly different) resistor/cap values could have a huge effect on a frequency filter like this. If your parts have high tolerances (say, 10%+), that could cause problems as well. Hope that’s helpful…let me know if you have any luck fixing it!

          1. Mike Ring says:

            I used the Radio Shack part numbers when I ordered, and the blue and green LEDs work just fine. It’s only the red/low frequency filter. I’ve just replaced the capacitor on the low filter as well as the transistor (in case either of those were bad).

          2. Mike Ring says:

            Low is up (after going through everything again) but now mid is out! Drat!

          3. Eric Weinhoffer says:

            Hi Mike,

            The kit creator, Aki (ledartist), has responded to similar questions on the original instructables page here: http://www.instructables.com/id/LED-Color-Organ-Triple-Deluxe/

            I’m looking at one question in particular that may be helpful to you: “Hi. I’ve followed your circuit and somehow my red leds are the only one light up (even before start) and there is voltage drop at capacitor 0.47microF. And i’ve change the values of both resistor at r3 and r4 to 20k.” His reply: “Try using larger value resistor for R3 and R4 til the red LEDs stop lighting. These resistor values change depending on the transistor used. You might have to use something like 100k ohm.”

            Good luck!

    2. sBeDs says:

      hi i came across the same problem, but found the solution, there’s a little mistake in the video, the last 2.2 resistor as to be connected from base to emitter, then the 1uf capacitor’s negative side to the base and the positive to a free row, then from that positive leg to the hub

  12. Virginia Phillips says:

    Hi again. We have finally assembled everything except for the 0.47uF electrolytic capacitor. Neither Sparkfun nor Radioshack has one of these – any suggestions?

    1. Eric Weinhoffer says:

      This one from Jameco (http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_330465_-1) should do the trick. If you’d like to have more capacitors around for later, I’d suggest picking up a whole pack of them, like this one: http://www.makershed.com/Make_Deluxe_Capacitor_Kit_220PC_p/mkee6.htm

      1. Virginia Phillips says:

        Thanks. In the 220 capacitor kit, looks like the .47uF capacitor is 100volt – does that matter? (sorry to be so clueless, trying to help my 10-year old son get what he needs, but I have no clue!)

        1. Eric Weinhoffer says:

          No problem! The 0.47 uF capacitor in the kit is rated for 100V, correct. Fortunately, that means that the component is rated for much higher voltages than your son will encounter in this project, so it will work just fine.

          1. Virginia Phillips says:

            Thank you so much. You guys are so helpful! This is the best resource for a child who is into these things and a clueless mom.

          2. Eric Weinhoffer says:

            No problem! Feel free to email me directly (eric@makermedia.com) if you have any additional problems getting it running.

  13. Shubham K says:

    If I wanted to add say 5-10 more LED’s per frequency (high/low/mid), how and by how much would the resistor config change?

    1. Eric Weinhoffer says:

      Well, in general making changes to an analog circuit like this is much trickier than if it were a digital circuit, just so you know what you’re getting into. That aside, the creator of the original project (http://www.instructables.com/id/LED-Color-Organ-Triple-Deluxe/?&sort=ACTIVE&limit=40&offset=40#DISCUSS) advised another person to do the following in order to power 12 LEDs instead of 6. Hopefully it will be at least partially helpful:

      “You can parallel connect two strings of two LEDs in serial. So for high channel, add another set of LED1, LED2, and 100 ohm. Now, this would draw too much current from the transistor, double the 100 ohm to 200 ohm. Do the same for mid and low.
      You get a bit less brightness on each LEDs, but this is the limit of this ‘simple’ circuit.”

  14. Duncan says:

    Hi I was wondering if it was possible to add more frequency I’m new to electronics but I would like to make this but with more ranges of colors please help me with a schematic or something

    1. Hi Duncan,

      In order to mess with the frequencies recognized, try double/half the capacitance or resistance of the filter circuit, to half/double the frequency of the circuit.

      Eric

  15. Vladislav says:

    is it possible to make something to stop red LEDs(low filter) stay turned on all time??

    1. Eric Weinhoffer says:

      Try using larger value resistor for R3 and R4 til the red LEDs stop lighting. These resistor values change depending on the transistor used. You might have to use something like 100k ohm.

  16. I made the circuit and it worked GREAT! Thank you!
    One question though, the LEDs I used were 3.2v .5watt, so they are dimmer than I would like. What would I need to get more current to the LEDs? Thanks!

    1. Eric Weinhoffer says:

      Hi Brian,

      In order to change the current that goes to the LEDs, I’d recommend trying different resistor values in the frequency parts of the circuit. Although, I wouldn’t make the changes too large to start — 50 ohms or so. Good luck!

      Eric

  17. rkan665 says:

    @Eric Weinhoffer does it matter what size leds you use/ i bought very large 10mm leds…it needs 3.2v how much does each bulb get? mines not working and i think its because i didn’t use smaller leds :P

    1. Eric Weinhoffer says:

      Yes, using smaller (5mm) LEDs will probably give you a better output in the end.

  18. Ben says:

    If I wanted to replace each pair of LED with one waterclear LED (to get brighter lights), should I replace the resistors as well, or would the current circuit resistors suffice?

    Thanks!

    1. Eric Weinhoffer says:

      Hi Ben,

      First, I’d try the circuit with the waterclear LEDs and see how it performs. It may be more similar to standard LEDs than you think.

      But, if that doesn’t suffice, I’d decrease the value of the resistors in the circuit by 50 ohms or so to start. That should help.

      Cheers,
      Eric

  19. Luckymat says:

    What resistor do i need if i want to run 1led or if i want to run 4leds
    I think for 1 i need 470 Ohm but im not sure …

    1. Eric Weinhoffer says:

      Hi Luckymat,

      In order to add another LED, just add it in series to each channel and double the resistance to account for the additional current draw (ie, go from a 100Ω to a 200Ω resistor) in each frequency band. You will get a bit less brightness on each LED when doing this.

      For running just one LED for each frequency, a 470Ω resistor should suffice.

      Eric

  20. Richard says:

    fun project… my lights are on even if there is no music playing… they pulse to the beat, but stay lit when the song is on… did I do it right?

    1. Richard says:

      err i mean when the song is done :/

      1. Eric Weinhoffer says:

        The kit creator, Aki (ledartist), has responded to similar questions on the original instructables page here: http://www.instructables.com/id/LED-Color-Organ-Triple-Deluxe/

        I’m looking at one question in particular that may be helpful to you: “Hi. I’ve followed your circuit and somehow my red leds are the only one light up (even before start) and there is voltage drop at capacitor 0.47microF. And i’ve change the values of both resistor at r3 and r4 to 20k.” His reply: “Try using larger value resistor for R3 and R4 til the red LEDs stop lighting. These resistor values change depending on the transistor used. You might have to use something like 100k ohm.”

        Good luck!

  21. alex says:

    I wanted to do this project using Adafruit’s NeoPixel Digital RGB LED Weatherproof Strip 60 LED. I wanted to make an 8X8 matrix (so 64 LEDs). The LEDS in the strip are all individually addressable. I was wondering what your thoughts are on this, would this work? Thanks!

    Adafruit’s NeoPixel Digital RGB LED Weatherproof Strip 60 LED:
    http://www.adafruit.com/products/1138

    1. Eric Weinhoffer says:

      Hi Alex,

      Doing something similar with an RGB LED strip would probably require a microcontroller or a large adjustment in the hardware. Googling “led strip music visualizer” will yield some helpful results.

      Eric

  22. anders1209 says:

    Is it possible to exchange the 2N2222A with an BC 548 and the 2N2907A with a BC 558?

    1. Eric Weinhoffer says:

      Hi Anders,

      Those may work ok, but honestly, the best way to find out is to just try them and see what happens! The specs are similar enough that it may work, but no guarentees…

      Eric

  23. audiobender says:

    In Step #6, should the instruction be to use the 0.047 uF capacitor? It says 0.47 uF.

    1. Eric Weinhoffer says:

      Yes, it should! Good catch. All better now :)

  24. Jordan says:

    is it possible to connect say, 10 LEDs of each color to blink in clusters? how would that effect the design, or would it?

    1. Eric Weinhoffer says:

      Hi Jordan,

      It is possible, but will require some changes in the design. Here are some notes from Aki (the creator of the project) on his Instructables page:

      “You can parallel connect two strings of two LEDs in serial. So for high channel, add another set of LED1, LED2, and 100 ohm. Now, this would draw too much current from the transistor, double the 100 ohm to 200 ohm. Do the same for mid and low.
      You get a bit less brightness on each LEDs, but this is the limit of this ‘simple’ circuit.”

      Eric

  25. Nadine says:

    If I don’t have an 0.47uF ceramic capacitor on hand. Can I use an 0.47uF electrolytic capacitor in it’s place? Or maybe an 0.1uF ceramic capacitor? Thanks!

    1. Eric Weinhoffer says:

      Hi Nadine,

      I wouldn’t go down to a 0.1uF ceramic cap – try the 0.47 uF electrolytic capacitor first. That should work just fine.

      Eric

      1. idoru00 says:

        Thanks! Worked out well with the electrolytic capacitor. Even modded it to use battery powered x-mas lights. Good tutorial.

        1. Eric Weinhoffer says:

          Woohoo! Glad it worked out for you.

  26. Peter says:

    Even though I’ve double and triple checked my wiring and components the circuit will only work if the battery is “lightly” connected into the circuit. Once too much pressure is on the wires or put into the circuit nothing will happen. Any advice?

    1. Eric Weinhoffer says:

      Peter,

      That’s strange.. I’d double and triple check the polarity of certain components (LEDs especially) again. If that doesn’t do it, maybe you just need to use a new battery? If you have a multimeter and can measure the capacity of battery, that may be helpful as well.

      Eric

      1. Peter says:

        Still not working.

        The resistors aren’t polarize, so that’s fine
        The strip of the diode is closest to the 1st transistor.
        LEDs legs are longer to shorter from left to right and top to bottom across the breadboard, theyre fine.
        I’ve tried 3 brand new batteries, all good.
        The cermamic caps aren’t polarized, all set.

        The only problem may be with the electrolytic caps. the .47 uF cap (50v) is actually a lot smaller than yours in the video but is the only one that has the strip (faces left). And the other 2 caps aren’t polarized (that’s how theyre made, got them through radio shack).

        1. Peter says:

          yet, I did shorten all the lengths of the legs of all the components except the LEDs to make it look smaller and cleaner…

          1. Eric Weinhoffer says:

            Peter,

            I don’t really know how to help you further.. it sounds like you’ve checked all potential problems. Judging by the symptoms (lights only “flash” and then turn off), I’d still guess it’s a polarity or broken component issue. By having one of the components backwards and plugging the battery in, you could’ve burnt out one of the critical components, possibly..

            Sorry I can’t be more helpful. Good luck!

  27. Marissa P says:

    Great circuit. However, in your schematic, you use different parts from those given on our parts list above. What transistors did you actually use? I’m trying to simulate the circuit now (and Q2-4 don’t exist on circuit-lab). My goal is to have each filter feed into 6 LEDs instead of 2. I’ll need to make a few buffers to make this happen. What do you recommend for getting the same brightness but with more LEDs? I am thinking buffers will work but will take up a lot of space. Thank you!

    1. Hi Marissa,

      We used three 2N3906 and one 2N3904 transistor for this circuit (you can see those with RadioShack part numbers by scrolling down in the parts list). For adding additional LEDs to the circuit, I’d recommend reading through the other comments, as other users have asked a similar question. But basically, for each channel, add another set of LED1, LED2, and a 100 ohm resistor. In order to account for the additional current draw from the transistor, double the 100 ohm to 200 ohm. Do the same for mid and low. You may get a bit less brightness on each LEDs, but this is the limit of this ‘simple’ circuit.

      Eric

      1. Marissa P says:

        Thanks for the reply. I did read through all the comments. I think with changing the R and C values on the filters we can maintain the same cutoff frequencies but change the current through the transistor. Perhaps this would be simpler with a MOSFET. I am trying to have more current at the LED output so I can get more LEDs to light up, brightly. I think op-amp buffers may work, but will be inefficient. So unlike the other posts, I was wondering if you have alternatives to this design (made for more LEDs) given that I understand it will be a more complicated circuit.

        1. Eric Weinhoffer says:

          Ah, I see. A MOSFET may be more efficient for accomplishing what you’re describing, but I’m not aware of an alternate, but similar, design. Since this circuit was originally designed by Aki, the LED Artist, and posted by him on Instructables, you may have more luck asking him for advice on that page, here: http://www.instructables.com/id/LED-Color-Organ-Triple-Deluxe/

          Sorry I can’t be more helpful – good luck!

  28. Deojo says:

    what if I just want to make one LED that only lights up when there is a mid Frequency, basicly just remove all low and high frequency component, then there is 2 led on mid freq, how of i just need one, sorry i dont really understand electronics

    1. Eric Weinhoffer says:

      Hi Deojo,

      Although I’ve never tried it myself, you may be able to accomplish that by simply removing the Low and High Frequency filter components.

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