Opa Alice build noise floor

[AUDIO FREQ]

Here is mine. Hissy hiss hiss

https://cdn.imagearchive.com/groupdiy/data/audio/90/90272-9499738494cba48efaa86320e94a92c4.wav

 

[oscarhuang]

I removed his 12v Zener diode. It can be said to be very quiet now.

 

[jp8]

I removed his 12v Zener diode. It can be said to be very quiet now.

Was it noisy before removal of the zener?

I know zeners are noisy, but that doesn't mean that noise will enter the audio path thanks to the excellent PSRR of the OPA. So I fail to see a relationship between removing the zener and low(ering) noise, if that was the message you wanted to convey.

I would not remove the zener. It keeps the ground return current DC, preventing potential Common Mode signal distortions.

Jan

 

[oscarhuang]

The hizz noise can be clearly heard before removing the Zener diode. After removing the Zener diode, the noise floor is reduced a lot. Maybe increasing the filter capacitor can achieve the same job.