query on the PSU of a preamp

[ray_ben]

Hello all,

I DIY a tube preamp based on a circuit from a old magazine.
It based on a 6DJ8 and 12AU7. I have some query on the power supply circuit. The circuit is attached.

Are the 2 Zener diodes (27V and 12V) in the right positions or they should be swapped?

Do you know the purpose of these 2 diodes?

regards, Ray

 

[hacknet]

i think its alright..

the 12v zener is to prevent the mosfet from destruction when the Voltage across the gate and drain exceeds the maxium allowable.

the 27v zener is supposed to do the same for the regulator.

 

[marconi]

between gate and source you mean...
But you are correct for the rest.