Help with LM386 Amp Circuit

[davenn]

Thank you all for your help. I completed it on some ic board. Now the only problem I'm having now is that I get some crackle from the speaker. Could it be from improper soldering or what?

show us a new photo or 2 of the board so we can see if you did all the mod's correctly
did you use a solder proto board ?

if so, why didnt you for a start just mod things on the breadboard and get it working before transferring to a more permanent soldered board ?

take a step back

Dave

 

[McDroogie]

I did both. It worked fine with the breadboard. I confused ic board with pc board. But it was a kit and it came with custom pc board. I did not solder the 4.7uf cap to pins 1 to 8; as it was optional. Do you think this could be the problem?

 

[davenn]

OK

that kit hasnt followed the established circuit for that IC as we have previously been discussing

But I think you will find your main problem is that you are grounding the input signal
looking at the photo it looks like you have the terminal that goes to the centre pin of the connector going to GND swap the green and black input wires around

Dave

 

[McDroogie]

Thank you it worked. I can't believe I missed that. When I desoldered the input signal I took the copper circle with the desoldering braid. I just scraped some of the copper on the pcb path and soldered the input directly to it. This has happened to me before. Is there anyway to avoid taking the whole copper coating when desoldering? Any tips?

 

[davenn]

Thank you it worked. I can't believe I missed that. When I desoldered the input signal I took the copper circle with the desoldering braid. I just scraped some of the copper on the pcb path and soldered the input directly to it. This has happened to me before. Is there anyway to avoid taking the whole copper coating when desoldering? Any tips?

yes , hot iron and quick solder/unsolder

if your iron isnt hot enough, it means you are likely to spend more time heating the joint up and this is more likely to dislodge the copper track

Dave

 

[(*steve*)]

Also:

1) clean, tinned tip;
2) don't "dig around" with the tip;
3) apply a little more solder if there is very little and/or it won't easily melt.

 

[quantumtangles]

I tried simulating your circuit (for quite some time) but could not get it to work.

Did not have an LM386 IC in the component database (used an LM358 and before that an 8 pin DIL) which may explain it. Retardation on my part may explain it as well.

 

[(*steve*)]

An LM358 is a very different beast to an LM386