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

No no no.

[fyngyrz]

You don't need vacuum tubes. That's such a horrible audio myth. They glow in the dark and look nice. Aside from that, they produce more distortion, more noise, use more power, are more fragile, and have shorter lifetimes than solid state electronics. They do not sound better, given $X spent on whatever, presuming some reasonable amount of tech is returned per dollar.

OTOH, if you just want to make vacuum tubes because.... you want to make vacuum tunes... have at it :)

Re:No no no.

[thegarbz]

You're conflating two different purposes for an amplifier. An instrument amplifier is part of the instrument itself. The choice of that amplifier has a significance to the music that is trying to be produced. Implying that all those famous guitarists chose tube amps because they are better at something ignores all the solid state amps that are used by musicians too. They have a different sound, not good, not bad, just different. Both when run normally and when overdriven. The choice of an instrument amplifier is purely artistic.

Well, I suspect this is essentially "remixing" songs. Adding a bit more depth, dirt, or warmth (from the noisy tube) might sound better but that's subjective, and it's all about personal preference.

This irks me. It's like saying that the Mona Lisa is nice and all but it should have been painted with more yellow. The purpose of a hifi amplifier is to reproduce the small signal as faithfully as possible, and with as little distortion as possible. Every design aspect should be based on the output being nothing more than a larger input, any modification to the signal should have happened before this stage (either in the studio, or if you really feel like not listening to the music as the musician intended then with a pre-amp). In that regard an interesting combination is often a vacuum preamp followed by a solid state tube amp.

But really the parent was on the money with the physics behind it. Tubes produce a more pleasing sound than a typical Class AB push pull amplifier due to harmonic distortion being predominantly odd order rather than the even order in solid state amplifiers. However in terms of being able to faithfully reproduce a signal in a larger form they are blown away in every metric (except power consumption, the GP got that wrong) buy a well designed Class A solid-state amplifier.

Now personally I think the Mona Lisa is too small.

Re:No no no.

[Bruce Perens]

Of course, modern solid state amplifiers aren't particularly power limited (at least if you have the cash) and should never be driven into distortion. Effects pedals give you whatever distortion you want and have the advantage that you can turn the amplifier some level other than 11 and you still have the distortion you like.

Re:No no no.

[TechyImmigrant]

The reason real guitarists prefer tubes is because of the distortion. Solid state just doesn't compare.

Well these days they do compare. Humans can't distinguish between an amp modeled on (for example) a Kemper modeling amp and the tube amp it modeled.
A few years ago it was not the case, but DSP always wins in the end.

Re:Yeah, no

[KingOfBLASH]

There are actually apps that let you run all kinds of emulations of classic amps and pedals. AmpKit is one that comes to the top of my head, but there's others.

Just plug an electric into your computer (using a USB interface) and you can push a button and sound like ZZ Top, or any number of presents.

You can also buy pedals that do this. (Just google Fractal Audio). Then plug right into the PA.

Re:Yeah, no

[FaxeTheCat]

There are a few videos on Youtube where some pretty experienced people try to find what is a real tube amp and what is a Kemper emulated amp. They fail. Not just fail. They FAIL. And admit it.
https://www.youtube.com/watch?...
https://www.youtube.com/watch?...

Re:Yeah, no

[rikkards]

Emulation has come so far in the last 10 years that Geddy Lee of Rush got rid of his amps and went direct into the mixing board through an effects board. So much room was saved on stage they filled the spot with chicken (roasters or washers and dryers if it was laundry day for the tour)

Re:Yeah, no

[judoguy]

And I would give the room more emphasis. I spent a lot of time building out my listening room. I have decent but fairly modest equipment but a kick ass room acoustically. I've been to friends homes with $40,000 worth of two channel stereo equipment in a living room and it was largely wasted. The sad fact is that it's usually way easier to spend money on equipment than to build out a room. I was very fortunate in that I was building a new house so I could design a space. Very few people have that luxury.