CD40XX integrated spectrum analyzer circuit based on the LM3914 display driver and used a total of 100 projects have two versions of Led pcb, diagrams, etc. The frequency list. There are all the files.
Spectrum Analyzer Circuit test
| Frekvencia (Hz) | R1 (Ohm) | R2 (Ohm) | R3 (Ohm) | C (F) |
| 30 | 10k | 12k | 47k | 330n |
| 60 | 4,7k | 10k | 20k | 330n |
| 120 | 2k | 15k | 9,1k | 330n |
| 250 | 10k | 39k | 47k | 33n |
| 500 | 4,7k | 43k | 22k | 33n |
| 1000 | 2,8k | 6,8k | 11,4k | 33n |
| 2000 | 1,2k | 6,8k | 5,6k | 33n |
| 4100 | 6,2k | 27k | 27k | 3,3n |
| 8200 | 3k | 10k | 15k | 3,3n |
| 16400 | 1,3k | 47k | 6,8k | 3,3n |
Source: http://www.freeweb.hu/pa-elektronika/spektrum_analizator.htm Audio Spectrum Analyzer Circuit pcb shematic Alternative link:
Audio Spectrum Analyzer Circuit ZIP File Password: 320volt.com
4X60Watt Amplifier Project TDA2052
TDA2052, AB class (+, – 25V) 60W working with symmetrical feeding (Music) output power amplifier is capable of producing. Low distortion and due to the AB class for Hi-Fi system may be preferred. Integrated the MUTE / STAND-BY feature can be turned off and the output can be controlled by digital circuits. In Integrated over-temperature protection and output short circuit protection are available.