Signal distortion

[fedail]

i have build this ciruit and i have distortion with negative

http://www.techlib.com/electronics/audioamps.html#LM386

this lm324 conect to dac and the output from dac is 0.1 mv so it is too small

 

[Roff]

i have build this ciruit and i have distortion with negative

http://www.techlib.com/electronics/audioamps.html#LM386

this lm324 conect to dac and the output from dac is 0.1 mv so it is too small

LM386 or LM324?

 

[fedail]

no.
lm386

 

[audioguru]

With a 9V supply and without a speaker, the max output of the LM386 is from +0.5V to +8.5V.
At the output of the 100uF capacitor the signal is from -4V to +4V.

The max allowed input of your ADC is probably from 0V to +5V so the signals from the LM386 might have destroyed your ADC.

But you said you connected an LM324 to a DAC not to an ADC.
I have no idea what you have connected to what. Please attach a schematic of what you have done.

 

[fedail]

i have repaire my problem

my dac is converted a big voltage so i reduce it and then connect to lm386
and remove bybas so that it give me



can u see if there is a problem to tell me

 

[fedail]

i have build this circuit on my minde not at rool if see any wrong just tell me

 

[Nigel Goodwin]

It's designed completely wrong!.

The ADC isn't biased, plus no coupling capacitor, then there's no coupling capacitor between the DAC and the amp, and the amp is connected up incorrectly as well.

Apart from that it's essential to low-pass filter both the input and output to prevent anti-aliasing.

 

[audioguru]

The positive power supply pin 13 VCC of the DAC is not powered.
Pin 2 and pin 15 are not connected.
The output from the DAC is a small current, not a voltage. It is connected to a very low value resistor and non-inverting input of a power amplifier, instead of the inverting input of an opamp as shown in its datasheet.

 

[fedail]

this samulation not show the power pin

how an i connect the coupling capacitor and resolve this problem

 

[bananasiong]

Apart from that it's essential to low-pass filter both the input and output to prevent anti-aliasing.

To prevent aliasing

Hi fedail,
The sine wave swings +ve and -ve. But the ADC is supplied with only 0 V to 5 V. Any voltage below 0 V is distorted because it's out of the range of the reference voltage of the ADC. So the input signal has to be shifted/biased up to the range of the reference voltages.

 

[fedail]

write i have build this with another circuit but i see in samulation it is not diiffrence if i have or not so i was remove coupling

but i think in real life i have to coupling thanks alot

 

[fedail]

i have add it

and read datasheet it must vref have 5 volt just

so i have distourtion
can u resolve this