As a little side project, I decided to make an audio amplifier for an iPod or similar mp3 player out of the LM386 op amp. Looking at the datasheet, I found that they already have designed a circuit that amplifies a signal by 20 (top left corner on page 5 of the pdf). Well, it seems detailed enough, but I just wanted to make sure my plans are sound so I don't somehow short circuit something and waste my precious, precious money .
Anyway, this is my plan: I'm going to hook up a 9v battery to pins 6 and 4 (Vs and ground, respectively). Then, I'll connect the the input from a 3.5mm headphone jack (probably connected to an iPod), to pin 3 (- input), and then back to the ground of the headphone jack. By the diagram in the datasheet, it looks like I'm supposed to connect pin 2 (+ input) to the ground on the 9v battery. I'll leave pins 1, 7, and 8 open (gain, bypass, and gain, respectively). Finally, I'm not quite sure what I'll connect to pin 5 (output). I searched around for speakers and came up with these 8 ohm, 2 watt (4 watt max.) from digi key. In the diagram in the datasheet, it says I'm supposed to connect a 250μF electrolytic capacitor (low pass filter?) between the output pin and the speaker, and a 0.05μF (ceramic?) capacitor between the aforementioned electrolytic capacitor and the output pin, leading to a 10Ω resistor and the ground of the 9v battery. Well, I couldn't exactly find any 250μF electrolytic capacitors (maybe I wasn't looking in the right places), so would it be okay if I used this 220μF capacitor from Radio Shack? If not, could anyone suggest an alternative capacitor?
Other than that, I mainly just wanted to know if my above plans were solid. If anyone sees a flaw in them, PLEASE tell me before I waste time and money and become extremely frustrated like the last time I tried a "fun" project like this.
Anyway, this is my plan: I'm going to hook up a 9v battery to pins 6 and 4 (Vs and ground, respectively). Then, I'll connect the the input from a 3.5mm headphone jack (probably connected to an iPod), to pin 3 (- input), and then back to the ground of the headphone jack. By the diagram in the datasheet, it looks like I'm supposed to connect pin 2 (+ input) to the ground on the 9v battery. I'll leave pins 1, 7, and 8 open (gain, bypass, and gain, respectively). Finally, I'm not quite sure what I'll connect to pin 5 (output). I searched around for speakers and came up with these 8 ohm, 2 watt (4 watt max.) from digi key. In the diagram in the datasheet, it says I'm supposed to connect a 250μF electrolytic capacitor (low pass filter?) between the output pin and the speaker, and a 0.05μF (ceramic?) capacitor between the aforementioned electrolytic capacitor and the output pin, leading to a 10Ω resistor and the ground of the 9v battery. Well, I couldn't exactly find any 250μF electrolytic capacitors (maybe I wasn't looking in the right places), so would it be okay if I used this 220μF capacitor from Radio Shack? If not, could anyone suggest an alternative capacitor?
Other than that, I mainly just wanted to know if my above plans were solid. If anyone sees a flaw in them, PLEASE tell me before I waste time and money and become extremely frustrated like the last time I tried a "fun" project like this.