Aikido + Phono section preamp

[athos56]

I've been gathering parts for a new preamp using old #56 tubes. Here is the pre-amp schematic so far. The Phono section can be switched in and out, the PSU is pseudo-dual mono. JB said that the 56 triodes should work well but they each need their own filament winding so that equals (8) 2.5v/1a transformers. I'm raising the heaters with the 50v bias tap from the mains transformer, halfwave rectified...

The output from the phono is mis-drawn, it should come off the anode of course.

[athos56]

Here is the power supply

[JoshK]

Why do they each need their own filament windings? I'd think one for the top ones and one for the bottom ones would suffice.

[athos56]

I haven't ordered any yet because of that reason. I think it had to do with the heater to cathode rating of the tube? I haven't been able to find what its rated for though. (4) 2.5v/2a transformers would be cheaper.

Sigh... I made the same drawing mistake on the aikido section...