I put together a circuit which is mainly the combination of two circuits I found on websites.
One is for inversion (inverting the left channel, combining it with the right and getting the result).
The other is a center channel.
The designs appeared in several places and seemed to be recognized as correct.
So all I really did was join them and add a bulb and a few switches.
When I connect a small 8 ohm speaker all I get is a hum. And this occurs even without input.
I am using two LM386 ICs which are mounted in sockets (to avoid soldering the IC leads directly).
They're tiny so I had to take care not too short any.
The connections have been tested for continuity (with the leads) and discontinuity (among the socket leads).
Does anyone have any ideas how to go about debugging this?
One is for inversion (inverting the left channel, combining it with the right and getting the result).
The other is a center channel.
The designs appeared in several places and seemed to be recognized as correct.
So all I really did was join them and add a bulb and a few switches.
When I connect a small 8 ohm speaker all I get is a hum. And this occurs even without input.
I am using two LM386 ICs which are mounted in sockets (to avoid soldering the IC leads directly).
They're tiny so I had to take care not too short any.
The connections have been tested for continuity (with the leads) and discontinuity (among the socket leads).
Does anyone have any ideas how to go about debugging this?
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You could post some photos of your build, measure and post the terminal voltages of the LM386 ICs making very sure not to short anything and post details of the type of 9 V supply. Hopefully that will give someone an idea about what might be going on.
Pin 2 and 3 of one op amp have no ground reference.
In addition, with a unipolar supply, your need some dc
biasing for op amp inputs. The circuit can not work as is.
In addition, with a unipolar supply, your need some dc
biasing for op amp inputs. The circuit can not work as is.
Correction : this IC seems to have internal "ground" reference.
You should describe what your intention is.
You should describe what your intention is.