B+ fuse

[joesatch]

Where would i put the B+ fuse in this layout?  Also what is the 150k resistor to ground doing?

[trobbins]

Imho, the fuse should go in one of the transformer winding arms.  The fuse type and rating can be determined by either testing, or design. 

The use of a zener in each winding arm is a concern.  In general, the zener needs to have a lot of design margin with respect to peak current/dissipation and to conductive cooling.  One could presume that the zeners are included to fit better with the output stage valves, but it could also be to include a voltage margin on the first filter capacitor - that all gets a bit dicey depending on mains voltage variation, and the exact power transformer being used.

It sounds like you may be trying to clone someone else's schematic - which is fraught with risk unless you intimately know all the parts being used and the application and measurements that have been made.

[joesatch]

- i didnt intend to use those extra 2 diodes.

- what is the 150k doing?

- i understand the risks and have decided to proceed with caution

[thetragichero]

150k resistor is to bleed the filter caps after power is switched off. i usually don't go this low in value

[dude]

Use 220k bleeding R, 3 watt

[dude]

Some Marshall’s put the 1/2 amp slow blow fuse right after the the rectifier; before the fist filter.

[uki]

Always a reference to look at >>>

http://www.valvewizard.co.uk/fuses.html

[pdf64]

And of course https://dalmura.com.au/static/Valve%20amp%20fusing.pdf