7 Band Spectrum Analyzer Circuit using OP Amps

Spectrum Analyzer

Circuit Preview

You can use this circuit for build your own spectrum analyzer for amplifier or any audio equipments.

In this post i will not show the sound level meter circuit and this is only the circuit of the band pass filter for the analyzer. you need to connect outputs of this circuit with sound level indicator circuits such as LB1403 , AN6877 to get full circuit. you need totally 8 of sound level indicator circuits. the last bar show the sound level and if you doesn't like it you can omitted that one and then you need totally 7 of sound level indicator circuits.

For build seven band pass filter here I used LA6458S. but you can use any operational amplifier for this. If you use operational amplifier such as LM324 or TL084 then you need only two ICs for this. because those ICs include four different operational amplifiers and LA6458S include only two operational amplifiers.

By using this circuit you can be able to get 50Hz, 100Hz, 330Hz, 1kHz, 3.3kHz, 6.3kHz and 12.5kHz output and these out put can be directly connected with any audio level meter circuit mentioned earlier.

Couple of year ago I found this circuit from a radio and then I build this one and it worked great..!
Supply voltage for this circuit is 12v.

7 Band Spectrum Analyzer