I have a LM 3886 lying around - does it work ?

[chazpope]

Hi

I have one of these left from a cooked 2 ICs Behringer amp - I suspect it was the other one cooked so I kept this one, I guess 50-50 it may work.

Is there any way I can test this with a meter other than building it into an amp first ?

thank you

 

[AndrewT]

Do you need to be sure?

If so then hit it really hard with a 3/4 kilogramme hammer. Now you are sure !

 

[chazpope]

Thank you for your kind suggestion, strange as it may seem I need to be sure cause I want to use it. It can go into a cooked bass amp but that involves unwinding the transformer to lower the psu ac output so I would like to know if it works before I start doing that.

 

[chazpope]

Surprised no one has anything to say re this ? Is it in a FAQ or what ?

I built the chip into a 4 resistor amp (muting bypassed) and I get nothing in the ouput, no great current drawn either

Then I measured that pin 3-out to 7-gnd is 33Ohms only - is that how it should be ?

 

[wazzy]

Surprised no one has anything to say re this ? Is it in a FAQ or what ?

I built the chip into a 4 resistor amp (muting bypassed) and I get nothing in the ouput, no great current drawn either

Then I measured that pin 3-out to 7-gnd is 33Ohms only - is that how it should be ?

try this it's about as simple as it gets and cheap too just for testing, test and see if you get any dc on the output this would indicate shorted output transistor if nothing input a signal and try it on a scrap speaker, hope this helps.

 

[chazpope]

Well that's exactly what I did - and I got absolutely nothing in the output, it behaves as if it is muted or as if there is nothing inside 🙂