DIY Acoustic Spectrum Analyzer: Schematics & Expansion for 10+ Lines, 40-LED Video Guide

Hello.
I would like to build something like the video:
https://www.youtube.com/watch?v=9SK2AxfELfw
Anyone have schematics for something like this?
Is it possible to do as in the movie 10 lines and later expand to more?
Schemes of lines and this "divider" are welcome.

If I chose the wrong department, please move it.

Thank you in advance for any help.

Ps. It would be good if these lines were 40led as in the video.

Series connection of LM3915 chips. Just note that the display is not multiplexed, which is terribly wasteful. These layouts cost a bit.

Added after 31 [seconds]:

Or do you have a cheaper and more economical alternative to this system? With this amount, a lot will come out ...

Kit from Chinese for $ 35.

The point is, these circuits are logarithmic and I will not give you a cheap alternative. If it were linear, the LMxxx series comparators are successfully used, e.g. in LPG level indicators in cars.

I was able to find the design of these lines and if I understand it correctly they are on lm324.
http://320volt.com/en/40-ledli-op-ampli-vu-metre/
But there is also the issue of this "filter" (excuse me, I don't know what it's called correctly) that splits a specific frequency into a specific line.

I don't know if you want to do it from scratch. You can buy a folding kit, it looks like this:
https://sklep.avt.pl/avt2864.html
And big ones are a different story and costs, the worst are the filters because you have to tune each one separately.

And how to make such a filter? And how is it dressed?

Read about analyzers built on microcontrollers. Search the web, for example, "atmega arduino led spectrum analyzer"

The appendix describes the multiplexed analyzer, which makes it possible to use only one VU-meter system. The LM3916 was used with a log-linear scale. The rationale for using bandpass filters is well explained, as is the principle of the multiplexer. As for the article that you provide at the link, the linear scale, as in the LM324 series connection, is not suitable for this and the circuit presented on jute would have to receive a compressed signal to show as it shows: is it with the help of a logarithm system, which I am somehow visually impaired here, or this with a dynamics compressor. So if I do not see such a system and in order to "patch a hole in the dynamics of the analyzer" a dynamics compressor was used in the form of eg a Winamp plug, then such a presentation is simply a fake. The necessity to use a logarithm system is dictated by the very high dynamics of music or speech expressed in dB. And here you need to know that this dB is not a unit, but it defines the measuring range of the VU-meter -> in this case voltage or power.

From the AVT 2864 chip:
Is it possible to replace the LEDs with 7 white and 3 blue ones, since their operating voltage is over 3v?
if so :
Do the values of the resistors change and what, can you leave the same, but you have to take into account that the diodes will, for example, "start later"?

I made my first analyzer on 20 UL1980 chips, 10 per channel. Red LEDs 220 pieces. The 20 extra ones were always on, i.e. even without music. I just added them. It was all housed in a large tower panel. A buyer was quickly found. The second analyzer is the multiplex analyzer from Praktyczny Elektronika (on LM) shown above. I made two plays as a stereo. I sold it without the housing.

Here is another diagram in an old book (1986).

It is worth looking at putty diagrams from other manufacturers
Jabel did so
http://bee.mif.pg.gda.pl/ciasteczkowypotwor/K...ik/J-74%20--%20Analizator%20widma%20-%20b.jpg

A colleague was building an analyzer from the Nord Elektronik set, I found that there was such a NE-091 kit, maybe someone will find a diagram

A long time ago I made a 10-channel circuit from Practical Electronics. It worked brilliantly.
Here you have a link to a page with all the issues of this great magazine from the old days:

http://webandy.hekko24.pl/PE/lista_pdf_Praktyczny_Elektronik_1992-2002.html

Download and see number 3 from 1992. In the next issue there was probably a reading field for 100 LEDs.
I recommend that you review all the issues and you will find many interesting and useful things there.

EDIT.

The readout field is in issue 1 from 1993.

You can also search for ready-made bars and add frequency filters to them. An example of bars as in the video at the auction Link . Especially this effect above (in the video) would be suitable.

And much better, you can do software on a minicomputer ...