Top of Power Supply (Left Chnl)   'Guess I think in a linear fashion cause I opted to arrange it physically according to the flow of juice thru the circuit.  R-to-L at top of photo is the ~375VDC B+ power supply w/ Pwr Xfmr.  The choke (far left) is purposely out off sequence in the flow in order to move it further from the input circuit of the amp.  Middle Row is the 300-B grid bias ~-110VDC. Almost in middle of board is the relay which dumps the B+  IF the grid bias fails.  The front row, from R-to-L is the 300-B filament xfmr followed by the plate supply for the 5842.  This could be a "stealth" amp if I used a black chassis top.   The round cans are Cerrafine electrolytics. 

 

Bottom of PS:   Nasty lookin' thang!  Those ugly discolorations are from using the breadboard as a template to jig up and solder (with propane torch) the copper pipe stands.  Remember, this is a prototype layout...... and we're havin' fun !

Conglomeration of haywire at front right corner is the power/filament switch assembly with IEC/filter input.

I'm using the switching method I discovered in an old old radio manual (see Glass Audio Vol 10 #2) Two DPST's.

Flip either one and filaments come up...Flip the other and B+ comes up.  Doesn't matter which switch is thrown, it properly sequences for on or off modes.     The shiny rectangle left of center is heat sink for B+ bleeder resistor...... without it, the breadboard smells like a campfire ;-}

Top of audio deck:   RCA input on right center.  5842 followed by the 300-B.  Machined an aluminum plate to mount the cerramic UX-4 socket for the JJ 300-B.  I needed to make the hole BIG on underside of this `3/4" laminated hardwood, to facilitate wiring the socket.

Notice that all iron is mounted with the end bells front to back with the exception of the interstage xfmr.  From a tip off of the Joe List,  I hooked a small SS amp up to the leads on the audio xfmrs and put on headphones, cranked up the PS and proceeded to move the audio iron around and around until I found minimum hum.  The interstage seems to favour a mounting perpendicular to the power iron.   Behind the Output xfmr is a plate with the speaker binding posts.   Little thingy to right of 300-B is the hum balance pot shaft.

 

Underside of Audio Deck:  Not much here, is there !

BTW  spacing between components is kinda' exagerated on all these breadboards.   I'm leaving space for any expansion/experimentation necessary.  When the design is finished,  I can then compact components and shorten all leads when making the aluminum chassis plate.

Your constuctive comments would be appreciated.

'Above pics were done with 640/480 casio digital camera.  The below pix were done using my Minolta 35mm  and processed on Kodak Picture CD.  Can you tell the difference?       Unless you're going to be taking a lot of pics, or need instant gratification, don't waste your money on a digital camera.