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

Covered in the past.

[Pikoro]

Here's a good one with links to more: http://hackaday.com/2016/05/04...

Re:Covered in the past.

[Pikoro]

And here's another: http://hackaday.com/2014/11/21...

Re:Covered in the past.

[arglebargle_xiv]

You don't even need vacuum tubes/valves, just build a valve sound simulator and you can get all the distortion and noise of the genuine tube/valve sound without any of the heat, fragility, and power consumption. It's a win/win situation.

Re:Covered in the past.

[zwarte piet]

It's an interesting idea, but do you really need a box with analog stuff for that? I bet the same can be done in software and then you can make profiles for different kinds of tube amps and tweak it to your own taste.

Re:Covered in the past.

[gordguide]

You don't even need vacuum tubes/valves, just build a valve sound simulator and you can get all the distortion and noise of the genuine tube/valve sound without any of the heat, fragility, and power consumption. It's a win/win situation.

They do throw some heat, they are far from fragile (otherwise every aircraft flight would be a throw of the dice, as there is no solid-state means of creating radar) and they use power because they are most often used in high-power applications where transistors simply cannot survive, even briefly (like, say, radar, terrestrial broadcasting, your microwave oven, and so on).

I am quite familiar with the digital simulations of vacuum tube audio sonics and tone, and the best they can do is come close. In no way do they sound exactly the same as a real-world vacuum tube circuit, which is why such devices still exist. They can emulate the sound in an mp3-kind of fidelity though, and generally they can only mimic the most eggrarious distortion modes of a tube driven circuit ... kind of like how TV Soap Opera Set colour mimics what you see with your eyes if you look around the room.

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.

[Anonymous Coward]

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

Re:No no no.

[Anonymous Coward]

But but but... you obviously haven't listened to hand crafted artisanal vacuum tubes using hand blown glass and mastodon hair wrapped with isometrically pure tungsten. The tungsten caresses the electrons in a way that's just not possible modern day transistors.

Re:No no no.

[KingOfBLASH]

Actually that's not true, just ask a guitarist (and IAAG - I Am A Guitarist!)

Vacuum tubes create a noisy signal, but in a weird coincidence, they do it in a way that is pleasing to the ear. The clipping and distortion sounds "warm," and there's an added depth in the sound (harmonics) that you don't get via transistors -- unless you create circuits that mimic the behavior of a vacuum tube.

Metallica? Tube amps. John Mayer? Tube Amps. Clapton? Tube amps. BB King? Tube amps. Eric Johnson? Steve Vai? Garth Brooks? All tube amps.

Of course, much of the "tone" we guitarists revere comes from overdriven and abused guitar tubes -- cranking up the volume on the tube so that there's massive distortion and noise -- which again sounds pleasing to some people.

Now, it's one thing to overdrive a tube or change the bias on it to get a particular sound from your guitar, what about building a tube amp to just listen to music?

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.

So, sir, you might argue that you dislike what a noisy tube does to your signal, but you can't say some people won't perceive it as improved, as it's about personal taste.

Re:No no no.

[Anonymous Coward]

So they waste your money sticking vacuum tubes in the circuit, then use solid state amps in the actual headphones. I'll stick with my original Koss ESP-9 electrostatics - they've stood the test of time without the vacuum tubes raising from the interior gimmick.

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.

Re:No no no.

[Anonymous Coward]

You cannot measure or quantify sound quality.

Yes you can. Hi-Fi equipment is suppose to *reproduce* the original as accurately as possible. This is something you can and people do measure. Hence the name Hi-Fi an abbreviation of High Fidelity.

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]

Just think of it as even harmonics, and it fits better into musical theory.

Obviously, what you really want to do is use amplifiers with sufficient power that they are never driven into distortion. And if you want distortion, get it from an effects pedal.

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:No no no.

[BlueStrat]

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.

As a pro-level guitarist for 4+ decades and who also has been designing & building tube guitar amplifiers for nearly as long, I have to disagree.

Distortion type effects pedals are attempts to imitate what goes on in a tube guitar amplifier being pushed to (and past) it's limits and some come close (and many more close enough for the average local artist/band in bar/small-gig venues) but it does not sound nor 'feel' the same to play through for a good guitar player.

Nearly all the flagship lines of the major guitar amplifier manufacturers are tube amps. Most pro-level concert/festival guitar amplifier backlines are tube amplifiers. Fender Twin Reverbs, Super Reverbs, and Marshall amplifiers (often vintage '60s/'70s era) are the vast majority of venue-owned backline kit provided for touring acts (and usually specified by the artist/band in the performance contract 'riders' section) at most large venues.

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.

The other problem with the inability to make tubes with fairly consistent and predictable performance and operational parameters is that it makes building things like the typical push-pull 2 or 4 tube Class AB1/AB2 power amplifier extremely difficult, as the tubes must be fairly close in there operational parameters or the unbalanced circuit will likely destroy the tube(s) of one side that conduct the most current. It would also be necessary to custom-wind output transformers to whatever plate impedance the tube(s) happened to exhibit

If you love vacuum tubes and spending exorbitant amounts of time & money mucking about with molten glass and exotic metals for fun, have at it. Just don't expect to build the equivalent of a McIntosh MC30 or a 100-watt Marshall using them.

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

Re:No no no.

[Solandri]

This whole thing reminds me of the filters people have come up with to modify digital photos to simulate different types of film

Re:No no no.

[Gibgezr]

The reason real guitarists prefer tubes is because of the distortion.

This is not entirely true. The dynamic known as "pick attack" is also something which solid state amplifier and DSP cannot reproduce with any level of accuracy.

 

Interesting, but Kemper disagrees with you. Their amps even have a "pick attack" knob.

Solid state just doesn't compare.

Solid state does many things well, but it has its own niche.

 

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.

Bullshit.

I call bullshit on your bullshit :)
Just watch the following video, where two experienced guitarists do a blind test: https://www.youtube.com/watch?...

Re:No no no.

[Lisandro]

As a former guitarist, i can tell you this: is not so much about the sound, but how tube amps react to ones playing. The old Line 6 stuff, f.ex, already sounded fantastic on recordings back in 1999 but didn't quite "feel" like the real thing.

Having said that: i haven't tried the latest state-of-the-art offerings from Kemper et al, but i hear this has improved a lot since then.

Already been done:

[Ellis D. Tripp]

https://www.youtube.com/watch?...

https://www.youtube.com/watch?...

Yeah, no

[fyngyrz]

Okay, we need to discuss classic amplification (IOW, not digital) and tube vs. transistor distortion. Applies to all audio reproduction systems - receivers, preamps, amps, headphone amps.

When run entirely in their linear range, which is to say, in class A amplification, where very expensive and/or high end analog musical system designs sometimes run, analog devices, be they tubes, fets or bipolar transistors, all follow the input signal faithfully, plus or minus total system noise and phase shifts -- no "warmth" or other characteristics are inherent in even a half-decent design, unless you add it yourself with tone controls or the like. *NONE*. For the record, tubes make the most noise, bipolar transistors next, various field effect transistor types the least. Analog integrated circuits tend to use bipolars and/or FETs; look the specific IC up to see, there's no telling otherwise.

So what you want, ideally, is the very minimum of distortion, noise, and as close to perfect signal reproduction as you can get. What goes in equals, as closely as possible, what comes out. But class A is an expensive and power-hungry way to do anything. So most reasonably priced tube and transistor linear amplifiers tend to run in class AB, which uses two devices or sets of devices at the high levek output, where one set amplifies the negative excursions of the signal, the other the positive set. The idea is that the devices are slightly on all the time, and when they begin to amplify their part of the signal, there won't be much distortion from moving into the linear part of their amplification curve from the non-linear, off, part, because the device isn't switching from off to on, it was already on. This works really well, and some very high end tube and transistor equipment works this way. Uses a little extra power, but it's a great compromise.

So what's different in a useful and interesting way between tubes and transistors? Well, when a tube is pushed into its nonlinear range, the gain transfer curve bends over comparatively smoothly so that what would be a sharply clipped (squared off) signal in a device like a bipolar transistor, turns first into a compressed signal, and even later down the curve, begins to evidence harmonic and other distortion that somewhat resembles that produce by hard clipping, but has, because of that still-somewhat-gentle curve, an entirely different set of dominant harmonics as compared to, for instance, a bipolar transistor at or near saturation. So the distortion, when the system is run so hard it distorts, sounds quite different.

That characteristic is why (knowledgeable) musicians who use distortion as a tonal tool often choose tubes; specifically because these musicians *do* run the tubes out of the linear area of the transfer curve, and the result is interesting -- and often pleasing. When the distortion is the result of a transfer curve that abruptly goes from highly linear to highly nonlinear, as is the case with bipolar devices, the result is most unpleasant. Edgy. Sharp. Dissonant. It isn't very often that such a thing is well received in a musical performance.

However, this choice does not *ever* hold true for a musical reproduction system based on tubes that isn't running in a range that will distort the music. You'd have to turn it up so far that one or more elements of the preamp or power amp is pushed past the linear part of its transfer curve, and then all of the music distorts -- and that's not a "warm" sound, that's a "hey, your system sounds awful, turn that thing down before I puke" sound.

So, for example, if I get out my Les Paul or my Strat and plug it into a tube amp and turn that bizatch up, I'm doing so because the amp's distortion is going to very significantly color the reproduction of what I play. I'm going to adjust the amp specifically so I *get* distortion. It'll sound fabulous. I'll get feedback, there will be awesome weirdnesses when I hit harmonics on my strings, pick and fretting artifacts will sound very different,

Re:Yeah, no

[fyngyrz]

You're welcome.

You can emulate anything, pretty much. You need a high enough sample rate, enough bits, and a complete understanding of what the effect does, and how it is controlled, if indeed it is.

If you skimp, you'll get... something else other than the original effect.

I write signal processing software pretty much every day. Here's my current obsession.

Re:Yeah, no

[sjames]

I think some of the confusion may be a holdover from way back when we were transitioning from tubes to transistors. What you said is true for good reproduction amps. But most people have/had mediocre amplifiers. They definitely don't have enough headroom to cover transients and the typical home stereo doesn't even have enough to not distort horribly when turned all the way up. Under those conditions, a mediocre tube amp would sound better than a mediocre transistor amp of that time.

None of that applies to current high end equipment, and there is no consumer grade tube amp unless it's a scam. But then audiophiles tend to believe in special signal conditioned directional cables, magic rocks, and tones through the telephone that somehow condition the room to sound better.

It may also be based on distant memories, but that warmth comes from nostalgia, not tubes.

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

[Anna Merikin]

Wow! Exactly what I've learned in fifty years of audio/broadcast production. I wish I had written it; I certainly wanted to.

I would give the speakers/headphones more emphasis, however. No matter how expensive your rig is, speakers as good will be more. Much more. Including the speakers (especially cheaply-made and poorly designed) in the system evasluation gives an edge to the way bipolar transistors handle transients or square waves. A high power-to-cone mass speaker will follow the sharply cut off curve of a transistor well enough to make a listener's ears bleed, that's true, but a low power-to cone mass cheapie will not; its physics actually complements the transistor's characteristics by not following its sharp peak, but taking its lazy time returning to its accurate excursion limit. In effect, a cheap speaker "smooths' the spikey output of an overdriven bipolar transistor or IC.

But wait, there's more! Psychology is the number one influence. We like what we are used to hearing. We get used to good audio over time, and we become more selective. Or, if we have only heard distortion all our lives, we get to miss bad production if it is absent.

Re: Yeah, no

[Jfetjunky]

You're pretty spot on. Just a few points to highlight. 1. Bipolar devices have the very lowest broadband voltage noise of widely used transistors, with field effect being a bit higher (but with significantly lower current noise). 2. Modern audio devices correct nonlinearities with excessive open loop gain and feedback. This gives them the knee point after which distortion vs frequency begins to rise (because the open loop gain begins to drop vs frequency). It works well but gives the "audiophiles" one more thing to point at, since most tube amps run multiple stages, each with a fixed amount of local gain. 3. The last is psychological, and it's something I had to force my self to come to grips with as someone who literally used to design extremely high performance audio test equipment: If someone thinks something sounds good to them, it sounds good to them. Just like taste or smell. Which is why the whole audiophile mythos exists. 5. 32bit systems are a joke. None of them have low enough noise. For high end systems the first 20 bits might be useful information , if you're lucky. After that the rest of thr bits are noise, and are, from a physics standpoint, hooked up to a gaussian random number generator. Happy listening.

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

[budgenator]

Yeah right, maybe ZZ Top could could like sound ZZ Top playing through an emulator to us, less likely to ZZ Top and You definitely wouldn't sound like ZZ Top, even playing on ZZ Top's rig. 80% of the magic is in the guitarists fingers, not the rig and not the guitar.
  Who really cares anyway, the kids today take a CD of some pop-star, with mediocre quality at best, rip it to a lossey MP3, load it on a smartphone and listen through overpriced headphone and think they are hearing music.

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.

Re: Yeah, no

[Anonymous Coward]

And one step further - the room the speakers are in can do horrible, or wonderful things to the audio as perceived at your listening position. (Usually horrible in domestic rooms.)

Spend a few bucks on corner traps and absorber panels (I like rockwool/mineral wool absorbers - effective, easy & cheap to build and look decent) and you'll completely transform your listening experience.

Re: Yeah, no

[Jfetjunky]

You're missing the point. The extra noise adds no useful information unless you apply statistics to improve the overall accuracy on a point by point basis. If the LSBs are dominated by noise, they are literally toggling in a random fashion. The rounding error, which in your example, might be 1 LSB, gets spread over the entire bandwidth of interest.

A SNR of 120dB, which is nearly unheard of except in audio test equipment itself, only requires 19.64bits to represent. It's a mathematical fact. Adding more bits behind that only makes marketing the product more fun.

The only thing that CAN happen, and used to happen, is getting stuck on a bit if the system level noise is well below the noise floor the converter is capable of resolving. This was possible back in the early days of audio, and is responsible for Dynamic Range being tested with a -60dBFS scale signal to force the converter to be excited through a number of bits.

Re:The tube is the easy part

[Crashmarik]

https://youtu.be/UcRTGVenN9U?t... Need to let those people know, they are using a mercury diffusion pump. I never made an amplifier tube but I sure as hell had to use the diffusion pump for my accelerator (Thank You C.L. Stong and Scientific American for publishing projects that would get people put in prison these days. How I long for my lost homeland)

Re:Apple pie from scratch

[Bruce Perens]

Would you make your own transistors?

Yes. If I could.

What is stopping you is that you think you need ultrapurification and microscale fabrication. No. Remember that the first receiving diodes were semiconductors, and while some used germanium it was not unusual to just use a rusty razor blade and the graphite point of a pencil. There are lots of semiconductor materials available to you, and making a cat's whisker is not difficult. It won't be the best transistor in the world, but it will amplify.

Tubes are still made here in the US....

[Ellis D. Tripp]

But generally only the exotic special purpose and transmitting types. The commodity 12AX7s and 6L6s for guitar amps are all made offshore, due to the low profit margins. The only audio types being made in the US are Western Electric 300B triodes, which are still being made in limited numbers for the high-$$$ audiophool market.

http://www.westernelectric.com...

Other remaining US tube manufacturers include CPI/Eimac:

http://www.cpii.com/division.c...

and MU, Inc. :

http://www.mu-inc.com/webstore...

, who apparently hang on making small runs of tubes to support aging military gear...

Re:Why anyone would ever be interested in tubes.

[hey!]

Sure but 1.3 KW is not "tremendous" power -- it's amateur range stuff. Broadcast AM stations go up to around 50kw, which is a "normal" for that application.

In the 30s and 40s, WLW in Nashville broadcast at 500KW. Radio Monte Carlo's transmitters currently put out 2x700KW in long wave and an even 1MW in medium wave. Russia's Taldom transmitter pumps out 2.5MW in long wave.

So I'd say anything over 10^8 watts is tremendous.

There are tubes that individually are rated in the MW range, like the 8974 power tetrode, which weighs 80kg and is water cooled. It is rated for 1.2MW (a.k.a. 700 horsepower); in class C it can peak at 2.1MW. That's what I'd call "stupendous" power.

I make tubes!

[Doctorglasseye]

Howdy all, I'm a scientific glassblower (25 years now), and I make my own tubes. I'm at www.incandescentsculpture.com; not much tube info there yet -been a few years in beta mode on them, but some other high-vacuum delights are to be seen. (My handmade incandescent bulbs, my Tesla wireless brush bulbs, the 'fuxie' tube....) Even the production of a simple, low-mu triode is non-trivial; the requisite equipment and knowledge take years to acquire, and a page long essay to even enumerate. OP, I'd be glad to help; perhaps we can compose a FAQ and parts list for kindred spirits.

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.

Poleaxed by your response

[fyngyrz]

But have you purchased your own telephone pole?

NO? Bloody amateur.