Hello and piece........

I foud this circuit on the internet and acording to my experience in electronics i see that i must work, so i transferred this to EAGLE and made a PCB for it, but when i connect a 9V (not from batt.) it started to produce weird sounds like a 555 time connected to a speaker and when i change the volume (potentiometer) the frequncy of the pulses changerd like 555 timer, but i barely could hear my vioce amplified.
What i sould to to fix my PCB?
Pleaze help!!!........

If anybody wants the EAGLE file i am ready to send, but give me your mail.
Thank you all................

 

Hello,

I see no decoupling capacitors in the given circuit.
Decoupling or Bypass Capacitors, Why?
You could try an capacitor of 10 - 100 μF and a 0.1 μF parallel on the pins 4 and 6 of the LM386.

Bertus

 

As you said you didnt use battery, did you try putting a 220uF across pin 4 & 6 of the LM386?

Allen

 

Why a poll? It makes no sense.

 

Tank you.
This is the first time to me and I don't know what are polls....
I will try the decoupling cap, should use bypass caps?

Shall I use a battery?

 

I would try a battery first to ensure that the problem is because of the power supply. Then, I would condition the output from the power supply and use it.

 

If the micriphone can hear the speaker then it will produce acoustical feedback howling as a sound goes around and around. When the volume control is turned down then the feedback howling will stop.

Try it with the speaker in another room with the door shut.

 

I Hello, thanks to all.
I added some decoupling capacitors every thing worker fine and clear.But when
i boxed it in a project box is stopped producing any sounds , not even nois.
And when i shorted pin 5 and 6 together i amplified sounds but the ic became hot
and the sound was unclear, so whats the problem and can i fix it?
Thanks.....

 

The datasheet shows that pin6 is the positive power supply pin and pin 5 is the output pin.
You should NEVER short the output of a power amplifier to its power supply.
You probably destroyed the IC.

 

Why would you short pins 5 and 6 together?

 

It was working good when i shorted 6 and 5, but became hot.

i just heared sound when i shorted them?!.....

 

Was it The swang song?

 

I shorted it but not damage it, i still works.....
Thanks

 

does the LM386 work properly when it is connected properly?

 

It is highly related to the passive components out.....and connections......

Can any body Help me please i still don't know what to do......

i think it is from a capacitor

 

You shorted the output to the positive power supply so the LM386 is probably blown up.
Simply fix the wiring and replace the LM386 IC.

 

I just wanted to see what will hapen..........I need any body to help me pleaze...I dont know waht the hell is happening in this circuit, it is just like....dead....Thank you.

 

I shorted it but not damage it, i still works.....

How did you reach that conclusion? What tests have you done to confirm the LM386 is ok?

It is highly related to the passive components out.....and connections......

How did you reach that conclusion? What tests have you done to confirm the the passive components caused the problem?

I just wanted to see what will hapen..........

And what did you conclude after you shorted those terminals?