Resistor color code

A resistor is the most important electrical component in almost every electronic circuit, it can limit current to any load such as led, transistor, opamp, etc. We must read resistor color code if we want to know the resistive value, tolerance, temperature coefficient. Resistors have different color bands (3,4,5,6) the more color bands the more resistor's information.Now let's start with 3 bands resistor color code.

The above resistor has only 3 bands First digit, Second digit, and multiply. A 3 bands resistor color code has fixed +/-20% tolerance that means if color code value is 1,000 ohms the real life resistive value may be +/- 200 ohms. 
4 band resistor color code

A 4 bands resistor color code has tolerance value color strip, the resistor on an above picture has 5% tolerance. This type of resistor uses in a regular circuit such as television,radio,washing machine.

5 bands resistor color code

A 5 bands resistor color codes have third digit color bands.
1(first digit) 0(second dig…

3 watts stereo amp board pam8403 sound test with jvc loudspeaker.

PAM 8403 is a class d integrated amplifier that sounds good and energy efficiency. The ic requires only 5 volts for full 3 watts stereo (2 amperes 5 volts power supply need for full power) with 83 % efficiency @ 4 ohms load, so this amp board is good for battery power.

This amp board sound good and fast respond but impact not good as pam8610 (high power version 10 watts stereo) but high frequency seem cleaner. Bass respond not tight(maybe my speakers are oversize)

The amplifier board work well with 1-metre speaker cable so this amp is very stable and no need big power supply filter capacitor to eliminate hum from a power supply (Bass respond will be better if you add 2200 uf/16 volts electrolytic capacitor parallel to power supply filter. Make sure you connect electrolytic capacitor with correct polarity!!! or ka-boom. 

PAM 8403 specification:

- 3W Output at 10% THD with a 4Ω Load and 5V Power Supply
- Filterless, Low Quiescent Current and Low EMI
- Low THD+N
- Superior Low Noise
- Efficiency up to 90%
- Short Circuit Protection
- Thermal Shutdown

If you plan to make a little amplifier that sounds good and energy efficiency so PAM 8403 is the right choice for you.

This video uses zoom h1 as USB mic for a nice result.
see sound testing video here.

See how to connect volume control to any amplifier board here

PAM8403 wiring diagram is here

See how to add a power supply filter capacitor to PAM8403 amp board to improve the amp board sound quality here 

If you need more power 10 watts 8 ohms PAM8610 is the best choice for you

You may love class T amplifier sound, TA 2024 is a low-cost high-quality amplifier board, see review here