Q: Zen-lite with -30~+30 voltage rail?

[Peter Huang]

I want to build a Zenlite cooperated with an existed power-supply with -30 and +30 voltage rails. Hence, I modified some points in the original circuit, as shown in the attached drawing.

Is it ok? Thanks.

[Nelson Pass]

Unfortunately, the design depends on very low noise from the
(-) voltage rail. In the original, that rail is ground, so there is
no problem. In your proposed modification, the noise at the
Source of the Mosfet will be amplified.

I suggest that you simply tie the V+ and V- together to form
V+ and ground, with the positive at twice the original value.

[Peter Huang]

Ya---Ya---Ya!!!
I missed the keypoints of a diferential pair and made such a basic mistake.
Thank you very much.

Cheers,