Ask Slashdot: How Do You Build Your Own Vacuum Tubes?

Could you beat wireless headphones by creating your own DIY home audio system? Two weeks ago one Slashdot commenter argued, "to have good audio that is truly yours and something to be proud of, you need to make your own vacuum tube amplifier and then use it to power real electrostatic headphones over a wire." And now long-time Slashdot reader mallyn is stepping up to the challenge: I want to try to make my own vacuum tubes. Is there anyone here who has tried DIY vacuum tubes (or valves, to you Europeans)? I need help getting started -- how to put together the vacuum plumbing system; how to make a glass lathe; what metals to use for the elements (grid, plate, etc). If this is not the correct forum, can anyone please gently shove me into the correct direction? It needs to be online as my physical location (Bellingham, Washington) is too far away from the university labs where this type of work is likely to be done.
Slashdot's covered the "tubes vs. transistors" debate before, but has anyone actually tried to homebrew their own? Leave your best answers in the comments. How do you build your own vacuum tubes?

Comments

Re:No no no.

[Anonymous Coward]

Spoken as someone who knows a little, but not enough about music engineering.

Tubes have been and are still used for ALL manner of instruments (including vocal) for "warming" sounds, saturation and creating distortion effects. The even harmonic distortion they produce when you overdrive are pleasing to the ear and can add an organic character to a recording that is otherwise lacking.
Different tubes produce different sounds so experimenting with your own would be interesting. For example: I remember replacing the 12V tube in my marshal amp with a recommended one to create more clear note definition when distorted - the results were pleasing and less muddy. (to me, remember this is a highly subjective area)

In music it is quite often the IMPRECISION that makes the bland great.

Long before we had the ability to simulate this electronically the only method to achieve this. In recent years however the simulated electronic solutions have come light years and it would be VERY hard for anyone to tell the difference between an analogue and digital tube distortion effect in a blind test.

So my advice would be twofold based on the questions:
1) Is doing this as a hardware project the point or just sound quality?
If the former, see point 2. If the latter then investigate the plethora of apps/plugins that simulate this.
While most are designed as VST (or other) plugins for DAWs, some of the best ones also have stand alone desktop app versions. You will get MUCH more variation to play with and in minutes rather than weeks.
e.g. http://www.ikmultimedia.com/products/amplitube4/

2) Why are you building your own tubes when they are cheap as chips and come in many flavors already?
If to experiment with different tube styles, go nuts.
If to simply increase sound quality, do yourself a favor and buy one or more as they are cheap. You could go a step further and buy tube DI boxes also which will do what you want out of the box.

Your good advice is useless.

[Zontar_Thing_From_Ve]

You said:

As to making a home-brew vacuum tube, it is doable but not practical. To get predictable performance mechanical tolerances must be exacting and the materials used in commercial tubes are rather exotic and difficult (if not impossible to come close to) for a home-brew vacuum tube maker. What you end up doing is making a tube using 'best guesses' and test/measure the tube's operational parameters and design the circuit around those parameters, rather than the other way around.

There is an amazing amount of exacting engineering, sophisticated manufacturing processes/techniques, and exotic materials science in the old commercial vacuum tubes even by today's standards and is pretty much impractical and beyond the means for the vast majority of private experimenters to reproduce in a home shop.

Strat

I've lived long enough to know that when some dude says "I want to build my own vacuum tubes" that he's not interested in hearing how unrealistic it is.