Step 4: Project: layout

Picture of Project: layout
Once you have the parts layout the circuit, please review the circuit and the layout pictures i've included. If any parts smell like burning or are hot, disconnect the power right away!

Pin 1: Unused
Pin 2: Ground of audio plug
Pin 3: To the Potentiometer  and to the audio plug
Pin 4: Ground
Pin 5: Power of speaker
Pin 6: Power from Regulator
Pin 7: Unused
Pin 8 Unused

Once its together plug in your iPod and rock out. You can control the volume with the knob. 
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Gisty221 year ago

can i put female audio jack instead of the speaker so i can connect it to my transmitter

natere21 Gisty2210 months ago

Yes. This is exactly what I did. I have a 1/4" TS (tip, Sleeve) audio jack instead of the TRS 1/8" mini plug shown in the tutorial.

natere21 made it!10 months ago

Thanks for the tutorial! nice little mono preamp. all you need is 2 of these, an regulated power supply (filtered!) and some power gain stages for an nice DIY stereo amp! :)

lm386amp 002.JPG
LGT3001 year ago
Can i use a 5k potentiometer
jdoeson2 years ago
Sorry I meant the 250uF electrolytic cap not film. The .047uF cap is film, and unused in my project.
jdoeson2 years ago
By the way - thanks for this instructable. A learning experience for us novices.
jdoeson2 years ago
What's the point of the .047uF capacitor and the resistor coming off pin 5? They don't seem to be necessary in my setup (part of the GND line?)

I'm using the 250uF film capacitor, but I tried using a few electrolytic capacitors that also worked fine (though had small volume differences): 100uF, 470uF and 1000uF.

I'm actually using this for a "HDD speaker". It sounds ok, and I can make the HDD actuator move pretty well with this, though I think I need to boost the voltage to make that sucker really dance.
AlexMayu3 years ago
I was wondering if I need any of the resistors and capacitors for pin 5 if for instance I'm just analyzing the output signal from pin 5 using an analog pin on a Arduino.
art.z4 years ago
Hi, I have a question.

Is a 220uF 35V capacitor enough for the output? Or it will have to stand higher voltages?
I noticed that the capacitor I have is smaller than the one you're using and I don't have a voltage meter to make sure.

Also, do I ground everything on the negative pole of the battery? Even pin 4?

Thank you!
Ririshi art.z3 years ago
Pin 4 IS the ground of the chip. Just think of putting a little lamp in a circuit to a battery, you would do the same thing. All other things with the gnd sign go to the - of the battery, too. I think your cap is enough, as I use a 10V and it didn't burn (lol).
jimmy5583 years ago
nice design...
but can clear the whole circuit of breadboard coz we not geting which pin of ic is connected with which components, plz make an other clear picture and also write info in description plz.
Thanks! I've been looking for a simple explanation to op-amps for a while. This is a great instructable.
gmuñoz13 years ago
I liked the model. But where the battery is connected?
kenkaniff3 years ago
I'm still new to circuits, and there's one thing I don't understand about your pictures...

Where exactly does the 9V battery connect to?
Rolcrz4 years ago
Hello! I read through your instructable and found it very useful and easy to follow. However, when building the actual circuit and powering it on, I encounter a peculiar problem: I seem to be catching radio stations! Even if I connect the jack to my mp3 player, all I hear is the same darned radio station! Any idea what could be causing it?
Misac-kun4 years ago
and if you put an potentiometer on pins 1 and 8? will it be able to control the volume?