So I hate valve amps (erm...'toob' amps). I don't like their sound. I don't like their performance. I don't like the fact that you have to spend a relative fortune to get a half-decent-sounding one.
Now you may disagree with any or all of that, but let's leave that to one side for the moment, because you can still help me out, even if you totally disagree. Isn't that a breath of fresh air.
I also think they look fantastic. I'm sure they're not everyone's cup of tea, but for me they look quite wonderful.
So I want one. But I'm not going to use it, at least not to power any speakers or headphones. I just want a set of massive, juicy glowing valves on my desktop.
And I want them to cost next to nothing.
Over to you for recommendations.
Many thanks.
Indeed. As they say:Voltage isn't what will end you, it's the amps.
It's the volts that jolts but the mils [milliamperes] that kills
The Boston Museum of Science has a nice one.I want a huge Van Degraaff.
Tubes are so passe.
The mrs could style her hair with it too. Maybe.
(Bonus WAF hopefully)
I always tried to work with one hand behind my back when delving into valve (tube) circuits! Back in the late 60’s I built quite a few amps using old UK WW2 surplus power transformers, chokes and paper smoothing caps. A good idea to put a bleed resistor across the caps so that you didn’t get a shock a week later!It's the 'lethal voltages' thing that puts me off the tube world.
Working around 600v gives me the heebies.
Since I didn't actually respond to the question -- I shall.So I want one. But I'm not going to use it, at least not to power any speakers or headphones. I just want a set of massive, juicy glowing valves on my desktop.
. . .
Since I didn't actually respond to the question -- I shall.
The cheapest route to glowing but useless tubes, in a 'plug and play' package, would be a two vacuum tube headphone amp or buffer available under any of about a thousand Chinese brand names. Thirty to fifty USD will get one. Almost all of them operate at low voltages and require no output loading. Most of them use small-signal triodes or pentodes, so the tubes themselves get only warm. All in all, they're (relatively) safe (assuming that the construction and circuitry is even close to reasonable standards!) and could be used with minimal worries as a display.
Here's an example: this is a headphone amp, and unfortunately only has one tube (a twin triode; two tubes in one envelope):
Here's a better example: This one is sold as a two-tube preamp, but it's pretty much cut from the same cloth as the above-mentioned buffers.
View attachment 352717
IN FULL DISCLOSURE: In many -- perhaps most (or even all) cases -- these little boxes cheat by sticking little orange or even yellow LEDs under the tubes to make them light up more vividly than they actually do. The little FX Audio box above is an example.
The best bet, IMO, would be to get two 'plinker' (inexpensive, even bad, used tubes that are worthless but with good filaments so that they'll glow), two sockets, some wire, and a "Hammond box" (or other little enclosure, bought or DIY) and build a box that is wired to light the filaments of the two tubes with a low voltage (generally 6 or 12 V, depending on the tube type). A 'wall wart' AC transformer will suffice nicely, as long as it can deliver the current required by the tube filaments. Tube manuals* list the filament requirements very plainly.
Then there's the brute-force approach. Assuming 120 VAC mains: Get yourself 10 12V filament tubes and wire all of the filaments in series. Connect one leg of the 10-tube-string to one prong of the AC mains, and the other leg to the other prong! For best results, add a fuse and, ideally, an isolation transformer. Plug in and enjoy.
Great for the holidays!
View attachment 352721
There is one other cheap-ish option, which I shall post separately.
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* Tube information (click on the 'spoiler' if interested enough!)
RCA tube manuals available for free download at https://www.worldradiohistory.com/BOOKSHELF-ARH/Bookshelf-RCA.htm
Here's a good one with "modern" but not too modern tube types, e.g.,
Here's a good "plinker" tube choice that will light nicely as long as the vacuum and the filament are both intact. As you see, it needs 6 VAC (give or take) at 0.3 amps.
Wire two of these (filaments only) in parallel and Bob's your Uncle.
View attachment 352720
Oooh. I just discovered that @amirm actually reviewed one of these
At which line on this graph does the 'good sound' start?
You forgot the biscuit tin full of cartridges.Absolutely! Double points if it actually works.
And, if anyone has a drawer full of NOS tubes for "rolling", they get a bonus immunity card they can play anytime to avoid being kicked out of the audiophile playground.
I have mine in a little wooden box, thank you very much.You forgot the biscuit tin full of cartridges.
I remember being told at one hifi show, many years ago, that anybody serious had a biscuit tin full of cartridges, and anybody knowledgeable knew which eight of them were the same model rebadged...
I'm sure that qualifies.I have mine in a little wooden box, thank you very much.
I'm sure that qualifies.
I can hardly talk... I only have one pair of speakers, so I'm obviously not serious myself. Just keep that between us, I'd hate to ruin what little reputation I might have here
Tubes 'n' racks go great together!Tubes make it so hard to stack/rack your gear but don't get the looking at tubes thing myself....or vu meters....or blue lights....
LOLTubes 'n' racks go great together!
View attachment 352792
PS: the plate voltage on the outputs in this RCA amplifier is lethal, full stop*.
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* With no pun intended, full stop.