Back-to-back PSU dilemma

[JimRayden]

A 9V-0-9V tranny gives me 18V which I kick back up to hi-V. I'm using the center tap for full-wave recto with 2 diodes, then I regulate the 18V to 12V.

The question is, will I be ok by joining the grounds from the rectified and smoothed hi-V and the heater (which connects directly to the center tap of the first trafo). Or will I be better off keeping them separated?

As far as I can think, as the B+ uses a diode bridge and the ground does not connect straight to the secondary of the second trafo, no voltage-feedback-effect or such is to be expected.

Any comments and suggestions welcome.

---------
Jimbo

[JimRayden]

I'll give it a friendly bump.

---------
Jimbo

[Paul Perry (Frostwave)]

If the secondary winding of the first transformer is connected to nothing but the primary winding of the second transformer then it shouldn't matter.
From an audio perspective, the thing is that there are small capacitances betweenthe various windings.
So you can get weird hum things happening when you stack up transformers...
but I think everything will go OK.

[JimRayden]

Thanks Paul. I'll report on the whole project when it's done.

---------
Jimbo