A few months ago I made a Vu Meter using IC LM3915. The results from the Vu meter are quite good for me.

And in this article I made another vu meter with a different IC. The IC that I use this time is the LM3914. This IC is still in the same family as the LM3915 IC. because it has a different series, of course I have different characteristics too.

And my goal to make a Vu meter using the LM3914 IC is to compare it with the LM3915 Vu meter that I have previously made.

Step 1: Required Components

The components needed to make the LM3914 Vu meter are the same as those used to make the LM3915 Vu mter, the only difference is the IC series used. And here are the components :

2* IC LM3914
12* Green LED
5* Orange LED
3* Red LEE
2* 100uF/25V
2* 0R 0805
5*2k7 0805

Step 2: PCB Schematic and Layout

The LM3914 has the same Pin and scheme. therefore I can use Schematic and layout of LM3915 vu meter.

Step 3: Order PCB on PCBWay

To make 2 Layer PCB with good quality. I use PCBWay service to make it. You can see the finished 2 layer PCB in the image above.

PCB order steps on PCBWay:

Visit the website: www.pcbway.com
Click PCB Instant Quote
Click quick-order PCB
Upload the gerber file by clicking "+Add Gerber File" and wait until the gerber file is finished uploading
Set the PCB specifications as you wish, starting from the number of PCBs, the number of layers, thickness, color and others.
After that, look at the left, it will display the estimated cost, processing time and delivery service selected.
Click Save to cart

Step 4: Inserting Components

After all the components and PCB are ready. The next step is to insert all the components onto the PCB.

This vu meter uses two types of components. Namely the SMD and Throughole components. To make it easier I put the SMD component after that the Trough hole component to be inserted,

Step 5: Results and Testing

Here is a photo of the LM3914 vumeter. for this vu meter there is nothing different from the LM3915.

For testing, I installed these two vu meters in parallel as shown in the second image.

and for the testing process you can see it on the video.

Step 6: Conclusion

there are three things that I can conclude, namely :

IC LM3915 & LM3914 have the same physical form, PIN, and scheme. so the LM3915 PCB can be used for LM314 and vice versa
When there is no audio signal on the vu meter, the first 2 LEDs on the LM3915 IC lights up and all the LEDs on the LM3914 are all Off.
The LM3915 IC is more responsive than the LM3914, it can be seen from the LM3915 IC LED that lights up more than the LM3914 IC at the same time