GreatScott! Hello, I love your vids! I am a young electronics tinkerer and your videos really help me understand how things work better. I am currently working on a maker fair project for the mini maker fair her in Minnesota and was wondering if I could use your design in my project. If so how would you like me to credit you? Thanks!
Yesss! I have so many vu meters, but never get tired of them. the lm3915 it is a very good option but lm324 it is good too. thanks for this excelente video my friend!!! saludos
OMG VU METERS ARE BOSS! I LOVE THEM! I HAVE ANALOG AND LED. Sweet! I'm not the only nut! I have a ton of old stereos from sansui to Marantz and Yamaha and Sherwood!
physics 12 student here and also not that smart.. but we are currently trying to do this project and have no ideas on which resister to use and where to use them! hopefully anyone can help? we bought all the resistors @greatscott mentioned in the description and are desperate to know which goes where
You know you're already a pro if you can place LED's and solder them neatly in just over half an hour. That would take me almost half a day just doing that lol. Great content would like to see more LED projects :>
this is so weird? yesterday i was looking for a LED VU-meter and couldn't find a simple / easy to follow design then you upload this a day later. awesome!
This would be a good project for using an LM3915 since otherwise you'd have to replicate this whole circuit for each frequency band. But, essentially, you'd just have the signal fed into a parallel array of band-pass filters, then fed into a copy of this circuit (or an LM3915) to drive each column.
That would turn out more like what we used to call a "3 Channel Colour Organ" that were very popular kits back in the early 70's and life was groovy. :) I still have one of mine that is operational. Typically the circuit sent the speaker level audio to 3 simple filters to get low, mid and high frequencies. Separate sensitivity adjustments for each channel. Those drove some circuitry that ended up at 3 triacs, modifying the AC that powered 3 banks of AC lighting. Using 3 flood lights was good for lighting up a family room wall or taking to parties or using out side at Christmas time in the front yard. Blue for low freq. / Red for mids and Yellow for highs. No ICs; all discrete components. We had to be careful because half of the circuit was handling full line AC voltage.
@@AKADriver I thought this video possibly would use an LM3915. I can't believe that part number came to me like nothing, though I haven't seen one in over 30 years. I had a bunch of them. My recollction is the 3915 was linear response and the 3914 was logarithmic, or the other way around. Plus I believe there is (was) an LM3916. Someone suggested slowing down the response which is a very good idea. If it's possible easily, putting in some peak hold would be good too. But at any rate when it came out, the series of chips opened up a lot of projects. I used them with 10 element LEDs in an IC package. Great for chassis mount meter projects, not for projection.
@@amaanqureshi1286 If you have some ee engineering experience you superiority complex gatekeeper, most people don't even for somthing like this, when you started out, you couldn't do this, stop being cocky and telling how it is so easy to everyone who has an opinion about it.
@@analogaudiorules1724 No it is very easy since it require minimal soldering skills. Just look at the circuit in the video, get the parts, and connect them. It isn't hard. I did things like this when I was 12 years old and hand zero experience or knowledge.
Even though I've only taken a few electrical engineering classes, I can't help but be a little happy that I do understand most (not all) of what he's talking about.
Ah Lochmaster! I designed a modular synth with stripboard with v3 of that software many years ago. Super cool software. It even lets you put resistors on the backside, and at odd angles, etc.. Massively useful. The site is probably still online somewhere. The ASM-1-SB edition. Good times!
Super sweet dude ! See if you could slap in a multi color LED disco ball that can be controlled with bluetooth to your future projects that'd be really neat as well.
It's very hard to doing these PCB without flexible wire lol. It make me remind to old circuit's project which is very terrible. Good job GreatScott! Keep doing short but awesome video!
As an industrial Q-solderer, I'm having a bit of pain watching you cutting component legs AFTER applying the solder. I know this is how a hobbyist gets the job done, I'm no stranger to it either, at least on prototype boards. Well anywho, great stuff, I like your projects and you've been a great inspiration for making projects in my home :) Keep up the good, no great, work :)
I had made vu meter using transistor and IN4148 diode. Each led has saprate transistor. But it required more power as input signal. I connect it with speaker output of an amplifier and add a 10 uf capacitor in signal line. Its results was great. It gives a little delay to fall down of led light and also led lightup brightly.
For version 2.0, get a bunch of capacitors/inductors to make resonant tank circuits and several of those chips to have crude but appealing spectrum analyzer!!!
I made one with just an Arduino. I connected a pc remote app to it and was able to sing live while it's dancing with my music! *************Details**************** I just programmed it so that the voltage that comes out of my laptop (analog signal) will be transferred into the Arduino board. Then, i chose the right voltage for the right LED section (LED line). I started playing music from my laptop. The data came out of the headphone jack (analog signal) then it started DANCING. I also connect an RGB light to the board so that it changes it's color depending if music volume is high or low. You can also replace the headphone jack with a microphone. But i like the headphone jack more.
Looks amazing, but I think there's a simpler way using just 1 OP amp, like this i.stack.imgur.com/QBMoj.gif Using 4148 diodes in series you can take advantage of their voltage drop to turn on the transistors below that threshold, just multiply the voltage drop of the diodes (0.65) by the number of LED rows (7), to obtain the maximum voltage at the output of the first OP amp (4.6). Finally, paralleling diodes without resistors is frowned upon due to current mismatch, but low power diodes aren't too fussy about this. Anyway, your videos are great, keep the good work!
I thought he was going to make this circuit, but he used so many ICs. I tried this circuit but I guess my diodes were defective, it didn't work Maybe I could use LEDs instead of diodes
I really like your videos, they are easy to follow, while they contain interesting subjects. What i do miss though, is a schematic in PDF format, or some kind of picture to download. If i go to the intructables page, i get a little image of the schematic, and it is really hard to see the components, and their value. So, a piece of advice for you, thanks for the videos though, keep them comming!
+Fiskelord and Friends (DK) You can download the image from Instructables with its original resolution. Just click on the Image two times and there will appear a couple of download options on the left.
Love your videos! I would really appreciate a more in depth look at how it works however! Like how you did the math to figure out all the dffirent resistors, mosfets, etc that you would need.
Really wanna build some big versions of this for my studio :D I don't thinks that's a VU Meter though; VU shows something closer to an RMS value (to approximate perceived loudness). Your meter (as well as tons of others on CZcams) looks more like a 'digital' peak meter. The needle in a VU meter has mass which slows it's movement down which give it that loudness property.
With RGB lighting being all the rage these days how about a project making your Great Scott LED sign (from your intro) using RGB LEDS with some of the effects that are found on keyboards (like the breathing effect)? Don't know how cost effective of difficult it would be and it might be beyond the scope of this channel, but it seems like that would be a nice project to me,
I built this circuit around 2 years ago, but upon completing the circuit all my leds are always on, whether an audio signal is connected or not. Is there an obvious mistake I’ve made? Any help would be greatly appreciated.
Hi Scott. From my point of view you can make this to be more simple. Instead of voltage comparators you can use an microcontroller such as Arduino or another microcontroller which has an analog and enough digital outputs and as the electonic switch you can use an bypolar transistor (PNP and NPN). Can you remake this video using an microcontroller, because this is very awesome project, especially for beginers.
It would be pretty cool if the 3th dimension was time. So that when you play music, the first "row" of LEDs shows the current state, the row after that the state of a moment ago, the row after that even a moment earlier, etc. I don't know of I get my thoughts across, but I am imagining a wave of music 😁
+vinno97 That would be awesome! Think about what kind of 3dModels this creates. But I dont know whether this is realizable with "simple" electronics(but I am more into Computer programming tho)
I have to say that I don't know as much as you, Scott. But I do believe that you could have achieved the same using less parts. Nice Video, waiting for the part with RGB LEDs :)
+Aryansh Malviya He wanted to show the concept, not only some abstract IC that does everything. But yeah, I also wouldn't bother to build it up as a discrete circuit, and just use a LM3916 or a micro with an adc.
For people who tell people who struggle that it's not hard, consider your own experience level or mechanical aptitude first, everyone is different. If you have some ee engineering experience, it is especially easy, if you have a confidence issue and feel the need to show off, you have a superiority complex and you're acting like a gatekeeper, most average people aren't even sure about something like this, when you started out, you couldn't do this, stop being cocky and telling how it is so easy to everyone who has an opinion about it.
Now imagine we use a low pass, bandpass, and a high pass filter to drive RGB LEDs (Each channel belongs to a frequency band) and apply the same principle. We already have a amplitude variable and we can add a frequency variable too
Man. After putting off learning how to solder and wire so long, I'm going to take the plunge and make this my first project....its way too cool not to!!!!
Could I suggest an easy, but effective mod for you circuit? Instead of just amplifying the signal, use the first op-amp to make the 'op-amp rectifier circuit'. Op-amp rectifier will not distort the output signal (and therefore give an erroneus VU output if just diodes were used, especially with low input signals), and, most importantly, will not insert any distortion back into the input signal. This is very important in cases where VU meter is connected in parallel to the audio line, for example between pre-amp and the power amplifier.
The best advantage of the op-amp rectifier is the VU output, which could be "slowed down" by adding a simple RC circuit to the rectifier output that would slow down the VU "fall-down" speed, thus making it steadier, less flickering , easier to follow the music, less "jumpy", and, most important, much more similar to the professional VU meters used in Hi-Fi equipment.
And one more thing - using logarithmic scale for comparator levels instead of linear (linear = 1V, 2V, 3V, etc) would make your VU meter look "more natural" and less prone to volume changes - i.e. linear design would make the VU to turn off most or all LEDs during quiet portions and lit most or all LEDs during loud portions of the music. (One example of logarithmic scale = 7V, 5V, 3.5V, 2.5V, 1.75V, 1.25V, 0.88V, 0.63V, 0.44V etc...)
Your videos just keep getting better
+MOVEMENT Thanks
GreatScott! Hello, I love your vids! I am a young electronics tinkerer and your videos really help me understand how things work better. I am currently working on a maker fair project for the mini maker fair her in Minnesota and was wondering if I could use your design in my project. If so how would you like me to credit you? Thanks!
Yesss! I have so many vu meters, but never get tired of them. the lm3915 it is a very good option but lm324 it is good too. thanks for this excelente video my friend!!! saludos
Como gusta verte por aquí Gastón :)
Yo también esperaba un lm3915
+maletil Essentially, an LM3915 is a single chip with coparators inside.
OMG VU METERS ARE BOSS! I LOVE THEM! I HAVE ANALOG AND LED. Sweet! I'm not the only nut! I have a ton of old stereos from sansui to Marantz and Yamaha and Sherwood!
You could also use the lm3914 for a Vu meter .C.
physics 12 student here and also not that smart.. but we are currently trying to do this project and have no ideas on which resister to use and where to use them! hopefully anyone can help? we bought all the resistors @greatscott mentioned in the description and are desperate to know which goes where
Wow ! I'm in the 2nd year of my apprenticeship in electronics stuff, and your videos are so helpful !
You know you're already a pro if you can place LED's and solder them neatly in just over half an hour. That would take me almost half a day just doing that lol. Great content would like to see more LED projects :>
You will get a better display by adding a small capacitor to the rectified audio signal, so slow the response of the meter.
togethia great idea!
rectified audio signal?? if u rectify the audio signal all you get is a small dc voltage that doesn't work.
this is so weird? yesterday i was looking for a LED VU-meter and couldn't find a simple / easy to follow design then you upload this a day later. awesome!
+AranE Games Cool!!!!
+The Master Gamer SWEDEN ( ͡° ͜ʖ ͡°)
I'd love to see a similar project with each vertical line linked to a specific audio frequency band, maybe with RGB LED for an even cooler look :o
This would be a good project for using an LM3915 since otherwise you'd have to replicate this whole circuit for each frequency band. But, essentially, you'd just have the signal fed into a parallel array of band-pass filters, then fed into a copy of this circuit (or an LM3915) to drive each column.
That would turn out more like what we used to call a "3 Channel Colour Organ" that were very popular kits back in the early 70's and life was groovy. :)
I still have one of mine that is operational. Typically the circuit sent the speaker level audio to 3 simple filters to get low, mid and high frequencies. Separate sensitivity adjustments for each channel. Those drove some circuitry that ended up at 3 triacs, modifying the AC that powered 3 banks of AC lighting. Using 3 flood lights was good for lighting up a family room wall or taking to parties or using out side at Christmas time in the front yard. Blue for low freq. / Red for mids and Yellow for highs. No ICs; all discrete components. We had to be careful because half of the circuit was handling full line AC voltage.
@@AKADriver I thought this video possibly would use an LM3915. I can't believe that part number came to me like nothing, though I haven't seen one in over 30 years. I had a bunch of them. My recollction is the 3915 was linear response and the 3914 was logarithmic, or the other way around. Plus I believe there is (was) an LM3916. Someone suggested slowing down the response which is a very good idea. If it's possible easily, putting in some peak hold would be good too. But at any rate when it came out, the series of chips opened up a lot of projects. I used them with 10 element LEDs in an IC package. Great for chassis mount meter projects, not for projection.
You make it sound like it's the easiest thing to do.
it actually is very simple.
@@amaanqureshi1286 If you have some ee engineering experience you superiority complex gatekeeper, most people don't even for somthing like this, when you started out, you couldn't do this, stop being cocky and telling how it is so easy to everyone who has an opinion about it.
@@analogaudiorules1724 No it is very easy since it require minimal soldering skills. Just look at the circuit in the video, get the parts, and connect them. It isn't hard. I did things like this when I was 12 years old and hand zero experience or knowledge.
Even though I've only taken a few electrical engineering classes, I can't help but be a little happy that I do understand most (not all) of what he's talking about.
Whenever I get bored,I used to watch greatscotts videos.. It's truly awesome.... Thumbs up man.. You're great
hi ! I am 14 years old and a great fan of your channel. greetings from India . keep up the good work!
Scott you are a real profesor !!!!! "its prery simple" he said ....
Yes!! The old intro is the best!
Ah Lochmaster! I designed a modular synth with stripboard with v3 of that software many years ago. Super cool software. It even lets you put resistors on the backside, and at odd angles, etc.. Massively useful.
The site is probably still online somewhere. The ASM-1-SB edition. Good times!
Super sweet dude ! See if you could slap in a multi color LED disco ball that can be controlled with bluetooth to your future projects that'd be really neat as well.
Dear greatscott you are the best, electronic youtuber
It's very hard to doing these PCB without flexible wire lol.
It make me remind to old circuit's project which is very terrible.
Good job GreatScott! Keep doing short but awesome video!
I like the layout of the boards you make it so neat and clean
Maybe you should try wire wrap, it's easy and practical to use when it comes to prototypes. Cool video, nice job!
who is a fan of scott but doesn't know anything he talks about ?
Present
Well, i'm not alone anymore :')
+Music Tests uhm no read more replies
Me.
^^^^^^^^^^^^^^^^^^^^^^^
same xD
Scott, du ist einer der besten CZcamsr. Awesome!
Looks Awesome!! The next thing to do would be a full K band spectrum analyser with the LED sign
As an industrial Q-solderer, I'm having a bit of pain watching you cutting component legs AFTER applying the solder.
I know this is how a hobbyist gets the job done, I'm no stranger to it either, at least on prototype boards.
Well anywho, great stuff, I like your projects and you've been a great inspiration for making projects in my home :)
Keep up the good, no great, work :)
You make it look easy! last time I tried doing a vu-meter I didn't sleep in 3 days
I had made vu meter using transistor and IN4148 diode. Each led has saprate transistor. But it required more power as input signal. I connect it with speaker output of an amplifier and add a 10 uf capacitor in signal line. Its results was great. It gives a little delay to fall down of led light and also led lightup brightly.
You are a force of nature!
3:22 At this moment I expected you to say "okay, I'm joking, we're going to use a simpler method"...But you didn't :(
That's super simple.
a true GreatScott again. awesome.
+emailausdrucker Thanks mate ;-)
Next project: audio spectrum in leds
It would be a good idea
I like that idea...
also interested
Hell yeah
You can do that quite easily using an arduino and the fourier transform library, the hard part would be to multiplex the led matrix
i like your post im electronic tech for 40 years now but I would like to do it again as a hobby thanks...
Long back I made a similar one with LM3914. Nice weekend project BTW!
am from colombia and your projectas are awesome
I have built a VU meter a while ago but I used an arduino and made 3 led bars for high mid and low frequencies.
For version 2.0, get a bunch of capacitors/inductors to make resonant tank circuits and several of those chips to have crude but appealing spectrum analyzer!!!
Probably the simplest way to do that is to use some LPF filters for the first couple letters and HPF filters for the last couple.
+Power Max That's actually a pretty neat idea!
You are an electronics god...love from india...
Impressive work! You make it sound so easy haha! We just built a sign with LEDs, wasn't that simple and we kept it very simple!
now add some frequency things and make each letter represent a different frequency of the music
Lol easy right? You'd need an arduino and the use of some FFT libraries for that.
@@minepro1206 You can filter audio signals without digitally processing it, like for example with capacitors.
i was going to build the same thing with a lm3914, so this video is verry helpfull. thanks and keep making awsome videos.
I made one with just an Arduino.
I connected a pc remote app to it and was able to sing live while it's dancing with my music!
*************Details****************
I just programmed it so that the voltage that comes out of my laptop (analog signal) will be transferred into the Arduino board. Then, i chose the right voltage for the right LED section (LED line). I started playing music from my laptop. The data came out of the headphone jack (analog signal) then it started DANCING. I also connect an RGB light to the board so that it changes it's color depending if music volume is high or low. You can also replace the headphone jack with a microphone. But i like the headphone jack more.
Once again Scott, great video and thanks for the knowledge. Greetings from Brazil.
You can make the application much easier with a LM3915 and 10 BD140 PNP transistors as LED drivers.
Hey you got the Barrel jack soldered to the board, Arnold! You are a GENIOUS!
Idea for a future project : Build a low pixel screen with LEDs
+Bogdi Gaming and More! For 720p he would need 921600 different pixels/leds. Even 144p is 36864 pixels.
***** 36p with a 16:9 ratio would be 2304 pixels. That would be possible but would take a VERY long time to wire.
+parasBanaani so it would be a multi episode XXL project
***** 18p would be 576 pixels and 9p would be 144 pixels. Im so tempted to buy a big bucket of leds and try this myself D:
parasBanaani if you do it pls let me know if you make a Video about it, I really want to watch it
Looks amazing, but I think there's a simpler way using just 1 OP amp, like this i.stack.imgur.com/QBMoj.gif
Using 4148 diodes in series you can take advantage of their voltage drop to turn on the transistors below that threshold, just multiply the voltage drop of the diodes (0.65) by the number of LED rows (7), to obtain the maximum voltage at the output of the first OP amp (4.6). Finally, paralleling diodes without resistors is frowned upon due to current mismatch, but low power diodes aren't too fussy about this.
Anyway, your videos are great, keep the good work!
Now That is clever🤔
I thought he was going to make this circuit, but he used so many ICs.
I tried this circuit but I guess my diodes were defective, it didn't work
Maybe I could use LEDs instead of diodes
You could add some capacitors to filter the analogue to make an actual VU meter. Cool.
good!
without arduino.
Very good . !!!
Next level VU meter ;)
i love u great scott iam a kid and i have been trying out your projects
Maybe separate columns and add higher and higher capacitor to ground to them. It may look pleasing.
Its great to see you working with ICs as opposed to just microcontrollers. I feel like the world has become too dependent on them.
Like always, You are Great !!!! Scott !!!
I really like your videos, they are easy to follow, while they contain interesting subjects. What i do miss though, is a schematic in PDF format, or some kind of picture to download. If i go to the intructables page, i get a little image of the schematic, and it is really hard to see the components, and their value. So, a piece of advice for you, thanks for the videos though, keep them comming!
+Fiskelord and Friends (DK) You can download the image from Instructables with its original resolution. Just click on the Image two times and there will appear a couple of download options on the left.
Nice, thanks a lot!
Now change the green leds with RGB and control them according to the music
Love your videos! I would really appreciate a more in depth look at how it works however! Like how you did the math to figure out all the dffirent resistors, mosfets, etc that you would need.
Really wanna build some big versions of this for my studio :D I don't thinks that's a VU Meter though; VU shows something closer to an RMS value (to approximate perceived loudness). Your meter (as well as tons of others on CZcams) looks more like a 'digital' peak meter. The needle in a VU meter has mass which slows it's movement down which give it that loudness property.
There is an IC that takes analog values and makes it into ten segments that go up and down based on the analog signal.
+Greg K Yes, it's called the LM3914. But I guess Scott wished to show people how to do it "from scratch"
Great video! Im still waiting for the LED Cube VU Meter Color Organ combo.
Nice video, greetings from Finland!
you're a good youtuber. everithing is explanated very well
Guy you are too much. Reminds me of my Dad.
well, that's a great beginners project! thank you very much Scott!
I love you videos , they are very professional , keep up the good work !!!
do it with rgb leds, pls
+CrissPivot www.waitingforfriday.com/index.php/USB_RGB_LED_VU_Meter
Master Yoda thanks
Can you make it stereo by omitting the resistors following the input jack and wiring L and R to separate circuits ?
this project is too good
Excellent project
I love Great Scott's video :)
Brilliant project.
THIS IS FREAKING AWESOME!!!!!
Why would anyone ask how you made the other one? Don't they see it played before the videos?
Now make each column a different frequency. So you get an audio spectrum.
That was a great project. Well done!
GreatScott is LED geek
Excellent video! I love your multimeter and scope too. Very nice.
I subbed a long time ago. Good videos.
With RGB lighting being all the rage these days how about a project making your Great Scott LED sign (from your intro) using RGB LEDS with some of the effects that are found on keyboards (like the breathing effect)? Don't know how cost effective of difficult it would be and it might be beyond the scope of this channel, but it seems like that would be a nice project to me,
Have you considered using an LM3914 led bar driver instead of your op amp construction? I think it might be easier to build. ;)
Make a portable gaming raspberry pi with the 2b model like the pigrrl, but by you, please
Like if you want it, if 100 likes, please make it scott
Really interesting video. My compliments Scott!
Hi there! Make a video about a digital and/or logic lithium battery indicator. that would be AWESOME!
Nice video! Maybe the next step would be to do this but with various audio frequencies to make an audio visualiser?
I built this circuit around 2 years ago, but upon completing the circuit all my leds are always on, whether an audio signal is connected or not. Is there an obvious mistake I’ve made? Any help would be greatly appreciated.
I just recently found a chip that condenses this circuit down drastically. It's called the lm3915
Hi Scott. From my point of view you can make this to be more simple. Instead of voltage comparators you can use an microcontroller such as Arduino or another microcontroller which has an analog and enough digital outputs and as the electonic switch you can use an bypolar transistor (PNP and NPN). Can you remake this video using an microcontroller, because this is very awesome project, especially for beginers.
please do a video on just how to make the led sign and power it by battery or mains if you cant with a battery
thanks man you have save on a summer shool electronic project
Some people like easy and simple. I love the music light board but I am not that advance.
Do you think this project can be combined with the RGB LED cube 4x4x4 or other size of the RGB LED cube?
+Fiedel Tegar Jiwandono Sure
It would be pretty cool if the 3th dimension was time. So that when you play music, the first "row" of LEDs shows the current state, the row after that the state of a moment ago, the row after that even a moment earlier, etc.
I don't know of I get my thoughts across, but I am imagining a wave of music 😁
+vinno97 That would be awesome! Think about what kind of 3dModels this creates. But I dont know whether this is realizable with "simple" electronics(but I am more into Computer programming tho)
+Simon Kochsiek yes I don't know whether this is possible with simple electronics. But it's definitely possible with an arduino (nano)
New intro
With new led board
I have to say that I don't know as much as you, Scott. But I do believe that you could have achieved the same using less parts. Nice Video, waiting for the part with RGB LEDs :)
+Aryansh Malviya He wanted to show the concept, not only some abstract IC that does everything.
But yeah, I also wouldn't bother to build it up as a discrete circuit, and just use a LM3916 or a micro with an adc.
Marian Keller That is what I am trying to say. man! :)
For people who tell people who struggle that it's not hard, consider your own experience level or mechanical aptitude first, everyone is different. If you have some ee engineering experience, it is especially easy, if you have a confidence issue and feel the need to show off, you have a superiority complex and you're acting like a gatekeeper, most average people aren't even sure about something like this, when you started out, you couldn't do this, stop being cocky and telling how it is so easy to everyone who has an opinion about it.
Why am I even here? I finished the entire video without knowing anything. I just felt like I'm awesome.
Now imagine we use a low pass, bandpass, and a high pass filter to drive RGB LEDs (Each channel belongs to a frequency band) and apply the same principle. We already have a amplitude variable and we can add a frequency variable too
Do that with color changing LEDs? Make a screen basically.
that's one hefty oscilloscope!
Nice and simple, should've used a different color for every letter though.
Man. After putting off learning how to solder and wire so long, I'm going to take the plunge and make this my first project....its way too cool not to!!!!
nice video.. I'm thinking I might take a crack at building my own version of it ☺
Could I suggest an easy, but effective mod for you circuit? Instead of just amplifying the signal, use the first op-amp to make the 'op-amp rectifier circuit'. Op-amp rectifier will not distort the output signal (and therefore give an erroneus VU output if just diodes were used, especially with low input signals), and, most importantly, will not insert any distortion back into the input signal. This is very important in cases where VU meter is connected in parallel to the audio line, for example between pre-amp and the power amplifier.
The best advantage of the op-amp rectifier is the VU output, which could be "slowed down" by adding a simple RC circuit to the rectifier output that would slow down the VU "fall-down" speed, thus making it steadier, less flickering , easier to follow the music, less "jumpy", and, most important, much more similar to the professional VU meters used in Hi-Fi equipment.
And one more thing - using logarithmic scale for comparator levels instead of linear (linear = 1V, 2V, 3V, etc) would make your VU meter look "more natural" and less prone to volume changes - i.e. linear design would make the VU to turn off most or all LEDs during quiet portions and lit most or all LEDs during loud portions of the music. (One example of logarithmic scale = 7V, 5V, 3.5V, 2.5V, 1.75V, 1.25V, 0.88V, 0.63V, 0.44V etc...)
Cool idea , but it would be cooler if the bottom rows were green and the middle rows were orange and the top two rows were red.
As always you are awesome!