• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Breadboard madness

"Two pins on the base of the tube socket are jumpered together. I am not familiar with this tube type, so I don't know if this is normal."

304s have a dual filament of 5V each at 12.5A. I assume a lot of people (including me) put them in series for lower current demand.
That makes sense. There is a 10 volt, 11 amp transformer on the "death board."
 
it was, once, literally, a board that someone had used to cut bread on...
In the era shortly after WWI, my grandfather made his old "crystal sets" (single galena crystal diode radio) on boards intended for cutting and serving freshly baked bread. Some were shaped like a large paddle with a handle, all cut from a single piece of Georgia Pine (he lived near Atlanta). His were meticulously crafted and looked as good as some of the commercial stuff of the day.

In the early 60's my DIY vacuum tube experiments used pine board scraps from the woodworker that lived next door to mount parts that had been removed from old radios and TV sets. They did look a bit like the mess discussed in this thread, but I could actually play my guitar through some of them.
 
Who needs a bread board when a fist full of jumper wires will do? (y)
Yes, this is my Tubelabs 300B amp. Even with the board and iron connected with a bunch of jumper wires it was dead quiet. I did build a chassis foe it eventually.
 

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Start with a working SSE amp, pull out the tubes and add a BIG handful of clip leads. Stir well, add a pair of 6LR8's on a turret board and feed it some electricity. Yes, this furball actually worked. Then simmer and distill down to the bare minimum, best served on a PC board. The SPUD is born. Also comes in a smaller package for speakers that are not so hungry.
 

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