LM380N Headpone amp.

Hi Guys,

Not sure if I am putting this in the correct section so apologies if not.

The sound from my PC is pretty dire (amp before so never a problem), just built up a amp based on the LM380N with a 15V 500mA regulated supply. All is working fine as I expect it would, It is basically the sound monitor from a matamp supernova.

Problem is it really starts clipping from 80% onwards, if I reduce the line input it is still the same. Any ideas or tips of things to check?

Wondering if the impedance of my headphones could be too high. Sensitivity 100dB/mW and 40 Ohm @ 1khz.
 

rayma

Member
2011-04-29 8:37 pm
All at work, have just got rid of all my personal test equipment due to space after a recent move.

Ok, then run a variable amplitude 1kHz triangle wave into it. See where it clips, on both polarities.
No need for a load. Is it close to symmetric? If the amp running on a single supply, is it still biased
to half the supply voltage at the outputs?
 
Last edited:
Are you wanting me to inject something like 1khz and follow the input to the output and see where it starts clipping?

It is certainly clipping on the output, I can control the input from min to max (connected to PC) even on 5% volume from the PC it is still clipping. I could try changing resistor values on +Ve
 

rayma

Member
2011-04-29 8:37 pm
Last edited:
Erm not sure if you can work out from the picture what is happening, it is in a test state atm.
 

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