"The Crocodile"
- Thread starter Shaq888
- Start date
Oh, thanks for correcting me. So opamps these days are really good at driving heavy load. I thought that opa1622 is already the best but there are many other opamps have similar performance.
@Shaq888: thanks a lot for those measurements 🙂
@proid: The advantage of the opa1622 for an headphones amp is that it is optimized to drive capacitive loads. The opa1656 isn't and the designer recommended to use an isolation resistor if used as a line or headphones driver.
@proid: The advantage of the opa1622 for an headphones amp is that it is optimized to drive capacitive loads. The opa1656 isn't and the designer recommended to use an isolation resistor if used as a line or headphones driver.
Hi Shaq888,
Can you help me check this: I follow your psu design, but using LM27313 instead and using power from 5V usb, it work quite well for light load, but with at higher load like 20ma i can hear it start to buzz and at 70ma, it's extremely loud. I upload some picture hope you take a look:
- first picture is the modified schematic, i just remove lc filter at output, and change some component value.
- second picture is the layout.
- third picture is the power supply noise floor without load, it's measured right at the output capacitor
- fourth picture is the power supply noise floor with 70ma load.
Can you help me check this: I follow your psu design, but using LM27313 instead and using power from 5V usb, it work quite well for light load, but with at higher load like 20ma i can hear it start to buzz and at 70ma, it's extremely loud. I upload some picture hope you take a look:
- first picture is the modified schematic, i just remove lc filter at output, and change some component value.
- second picture is the layout.
- third picture is the power supply noise floor without load, it's measured right at the output capacitor
- fourth picture is the power supply noise floor with 70ma load.