PSU questions - adding la2a to tube pre

[BluegrassDan]

Draft schematic here:

 

[bluebird]

yes I would remove R30 all together. If your lucky it will stay at 295V but I have a feeling it my dip a little under load. If it dips too much like to 280V the regulator might not be able to filter out all the ripple. You may have to adjust the zeners for a little lower voltage. I found with 20V to be the perfect differential using a TL783 voltage regulator Good balance between power dissipation and ripple rejection. This circuit works differently than that so results might be different. Just try and see.

 

[BluegrassDan]

I measured the voltages under load in one of the preamps I've already built. Of course, we also have higher wall voltage where I live.

 

[bluebird]

Of course, we also have higher wall voltage where I live.

Thats why you want a healthy differential between the raw DC and the regulated DC. If you use your equipment in another state or if there is a strain on the grid in the middle of summer and the voltage is a little low, you want to be confident your not gonna have some background hum on the vocal track.