Wow, I should build one of those… sure beats soldering tag leads to the socket and plugging them into the breadboard, transistor style (like I do now…). I do worry about how much of an effect all that capacitance from the breadboard has on those hi-impedence circuits, though. It’s why I never expect it to sound exactly the same when it’s wired point-to-point. Nice hack, simple and well thought out!

You can find these ready-made…if you’re willing to go back far enough. I used to have a tube breadboarding kit from the ’50s which fit into a large wooden suitcase. It included a variac-adjusted power supply and several drawers of tube sockets and various discrete parts mounted on plastic carriers with metal pins for electrical connectivity. The front of the suitcase was lined with perforated pegboard; you snapped parts into the pegboard and connected the pins with jumper wires. The whole thing was so cumbersome and problematic that I only used the power supply, and eventually junked the rest. (Boo hoo!)

It really highlights the sea change brought about by transistors; all that junk was obviated by a solderless breadboard you can fit in your pocket. Tube prototyping still requires a lot of fabrication and this guy has done a great job. A++ for literal breadboarding! I’d be concerned about the reliability of a solderless breadboard at typical plate voltages of 150-450VDC though.

Here’s one of my own tube prototyping aids–a 6.3VAC/300VDC power supply built into some old hard drive cases.

http://reboots.g-cipher.net/projects/theremin/image/powersupply.jpg

please tell me there is no high voltage on breadboard

Re: Reboots
I am (slightly sad) to say that I have used a modular breadboard in excess of 250VDC without incident. Of course, I never actually /trust/ it to be safe…

I have routinely put 300VDC on cheap breadboads without issue. The trick is to make sure you don’t have any large voltage differences between neighboring columns. As long as you space everything out, there is really no problem. You might notice that this guy has at least 5 columns between every connection. I usually avoid using the rails, but I am not sure that matters too much.

When I was a kid one of the electronics experimenting boxes I received had a breadboard full of holes and spring fixtures to connect the components together solderless. There were no tubes of course due to the thing being oriented to kids, but that arrangement would be very useful for tube prototyping.

Surely some Devry solderless breadboards from the vacuum tube era can still be found. No doubt when used sensibly this could meet the needs of many if not most.

Those plug-in boards make for nice distributed capacitance arrays! It would be rough to proto anything of super-high impedance. However, with adequate layout considerations, it could be quite handy! Just don’t try to do anything with DC-to-daylight bandwidth. Or anything with a lot of dv/dt. FRATZ!