Hi,
This is my first audio project, I built a CMoy amp usingthe schematic for the Crystal CMoy here: https://www.instructables.com/Crystal-cMoy-Free-Form-Headphone-Amplifier/
All seemed fine except the sound was distorted, so I hooked it up to a signal generator and o-scope.
The attached images show the input 1 khz sine wave along with the output. The output is amplified, but is clipped and looks more like a triangle than a sine wave.
I did this with the amp powered from 18 vdc.
It's possible the outout is a sine wave, and it's just the scale that makes it look rather linear, but what is the likely cause ofthe clipping? Too much gain? In out too high (about 2 vdc p2p).
thanks,
James
This is my first audio project, I built a CMoy amp usingthe schematic for the Crystal CMoy here: https://www.instructables.com/Crystal-cMoy-Free-Form-Headphone-Amplifier/
All seemed fine except the sound was distorted, so I hooked it up to a signal generator and o-scope.
The attached images show the input 1 khz sine wave along with the output. The output is amplified, but is clipped and looks more like a triangle than a sine wave.
I did this with the amp powered from 18 vdc.
It's possible the outout is a sine wave, and it's just the scale that makes it look rather linear, but what is the likely cause ofthe clipping? Too much gain? In out too high (about 2 vdc p2p).
thanks,
James
Just too big?? Looks like 8 volts or 16 volts peak-to-peak. Which would BLOW YOUR EARS OUT. So the 'scope pictures are probably not what you are really listening to.
What test load are you using?
The plan shows gain of 11 which is probably far more than you want.
You may have noticed that headphone amps and integrated speaker amps have volume controls. Source devices in an audio system may output about 4vp-p which will overdrive amps not having volume controls. Your project is neat and interesting but I see no volume control.
Thanks for the replies. I'm going to attenuate the source and seeif that fixes things. I suspect the intended source for this design is a cell phone which likely has a low output