Who says that TUBES = RETRO?

There are tubes ,and tubes .Tubes are still used in RF .They can produce hundreds of watts of output power in a very straight forward manner. I used to design 2Kw Commercial broadcast FM transmitters 25 years ago.My emitters were hand crafted .All done by hand with love .Like those italians masters used to make violins .Smith charts .Ceramic Tubes by Varian .matching equations for resonant circuits made of copper piping .Oh those were the days .Forget all about broadband ,all about complicated digital modulating schemes .You could see the power .it made the tubes glow .
No microprocessor any where just a grid current meter .I never felt so alive .

Well anyways.Here we are now .Put some DSPs,some Adc converters ,Some LCD screens and Complex modulating schemes .The sky is the limit .I'm seriuos you can even use them for RADAR systems if you can design FPGA radar signal processing units . So Tubes are not dead .They are just one more toy to me!

eltonjohn said:

There are tubes ,and tubes .Tubes are still used in RF .They can produce hundreds of watts of output power in a very straight forward manner. I used to design 2Kw Commercial broadcast FM transmitters 25 years ago.My emitters were hand crafted .All done by hand with love .Like those italians masters used to make violins .Smith charts .Ceramic Tubes by Varian .matching equations for resonant circuits made of copper piping .Oh those were the days .Forget all about broadband ,all about complicated digital modulating schemes .You could see the power .it made the tubes glow .
No microprocessor any where just a grid current meter .I never felt so alive .

Well anyways.Here we are now .Put some DSPs,some Adc converters ,Some LCD screens and Complex modulating schemes .The sky is the limit .I'm seriuos you can even use them for RADAR systems if you can design FPGA radar signal processing units . So Tubes are not dead .They are just one more toy to me!

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I agree ofcourse they are not dead. But their low power or discrete application is dead almost except for high frequency and high power.
Even discrete Transistor designing is rear now. Let me more elaborate that even designing with basic logic level IC is replaced by MCU, DSP's and FPGA etc.
Now modular concept is more desirable and available, because of time and cost.
You see new students/Professionals now have many tools available to simulate so they thought why to go hard way with more time and cost.

Regards

I took my electronics classes back in 1990-1991 and we barely touched tubes. In hindsight that is one of my regrets. I had always wanted to learn circuit design using tubes.

I was in the last tube theory class that was taught at my high school. Years later I worked at a company that made some of the subcomponents of modern electron tubes. Times and technology change but the physics remain. Now we have wunderkind microcontroller programmers on edaboard asking how to make hardware work.

I grew up on 6L6 amplifiers and 807 PA stages which shows how old I'm getting. Sadly, my junk box is now full of microprocessors not glass tubes.
Take a look at this though: YouTube - hand making vacuum tubes Part 1

They still have many uses. Some years ago I visited a company that made RF power transistors. When they demonstrated one of their products they used a TWT to drive it. The reason was the wide bandwidth, wide power level, and linearity.

Tubes are retro

OK guys,
tubes WERE retro, why? Very simple reason. People thought silicone technology was the ideal solution, less size, less weight, less power (higher efficiency), theoretically no wear. And they are right about this. Now the tube factories again are beginning tube production in the Russia, China, USA etc. The very simple reason is when the signal is being amplified by a transistor (which is no more than an silicone valve) it generates internal noise (because the electron current is interacting with the silicone structure) and thus modifies the signal being amplified. In vacuum valves the current flows through vacuum, so the signal is much more close to the original. The other very important reason is transistors have to work with deep negative feedback, which causes generation of high order harmonics that are injected into the amplified signal. Tube amplifiers can work without any (or if it's necessary - very small) negative feedback. This way avoiding high-order harmonics. This is very clearly heard on an valve audio amplifier. Please hear one before making retro posts here. Nowadays more and more audio enthusiast turn to vacuum tubes again, because of the sound quality. It's not weird that the most high - end audio systems (HI-FI is a class that stands much below hi-end) are based on tubes. There is a plenty of literature, DIY projects and authors to ask, please don't write things unprepared.

Vacuum tube amplifiers had the distortion increasing every day before they completely failed. Some bands replaced the tubes for every show.
They provided little damping to control the resonances of speakers.
Their output transformers rolled off low and high frequencies.

Solid state amplifiers have extremely low distortion and noise. Their performance does not deteriorate and they rarely fail.
Their output impedance is extremely low to control the resonances of speakers.
Their low and high frequency response is excellent.

Solid state amplifiers are not silicone, they are silicon.

Audioguru said:

Vacuum tube amplifiers had the distortion increasing every day before they completely failed. Some bands replaced the tubes for every show.
They provided little damping to control the resonances of speakers.
Their output transformers rolled off low and high frequencies.

Solid state amplifiers have extremely low distortion and noise. Their performance does not deteriorate and they rarely fail.
Their output impedance is extremely low to control the resonances of speakers.
Their low and high frequency response is excellent.

Solid state amplifiers are not silicone, they are silicon.

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Yep, precisely true. I'm not saying tubes are perfect, I'm just saying they sound much more natural than SS. Anyway distortion of tubes has different nature from distortion of Solid state and thus measured the same way they are not equivalent when heard. Tubes most common distortion is more like amplifying the one halve of a sinusoidal signal less than the other. SS most common distortion is like limiting the output signal. Now tube distortion of 5% is barely barely heard, but SS distortion of 2% may make you go crazy. These are not the only one effects that causes distortion of course, there are much more. Furthermore SS is capable of giving much more power and very deep bass for instance, which average tube amp can not compete. But power does not mean true pleasant sound, sound when heard makes you smile, makes you warm and comfortable, sound that can be listened for hours and hours with pleasure. This is the big advantage of tubes that no SS can beat yet. Anyway there always will be SS are better that tubes and vice versa, this is a choice that only the listener can make. This is my choice and I don't want you to change your systems with tube ones, no. Just want you to listen to one before judging them.

Referring to live music equipment mentioned by Audioguru, you'll see that legandary brands as Marshall, Vox, Fender, Orange or Mesa Boogie still have large market shares. Most of their amps are still pure tube, some hybrids with solid state preamps, others SS power stage with tube preamp. All solid state types have some digital or analog effects that model a tube characteristic.

I assume, that nobody will intentionally overdrive a solid state output stage, you risk to damage the speakers, at least the sound will be awfull.

So if you say tubes are retro, than all the rock music business is retro, too.

I have seen extremely expensive amplifiers with vacuum tubes glowing on top.
But the amplifier circuit is completely solid-state. The tubes are only for show.
People who throw away their money to buy them don't know.

Yesterday I went to an old restaurant that has a new name. The retro juke-box played music from the 60's. It was distorted, muffled and boomy so it probably had vaccum tubes.

The tubes are only for show. People who throw away their money to buy them don't know.

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Artefacts like this can be found in the "high end" audio segment. I notice, that some serious audio freaks still love (true) tube amplifiers for HiFi. But I don't actually know details of their amps. But they have surely low distortion.

60th juke boxes have poor amplifiers (and disc pickups, too). Generally, there's a big difference between a low linearity and restricted frequency response amplifier used for reproduction of a complex signal and a guitar amp. The former will always sound mushy and misses any transparency. A tube guitar amp is a completely different thing.

Audioguru said:

I have seen extremely expensive amplifiers with vacuum tubes glowing on top.

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I'm sure that there are companies that take advantage of ignorant people but there are many companies
that have names well known in tube amplifier lovers like
Kondo - Audio Note
Jadis Electronics
Audio Research Corporation
Welcome to conrad-johnson

Personally I have never used a tube audio device but I have read many reviews in magazines that praise the audio quality of tube amps.
Sure these tube devices are more picky in loudspeakers load and are usually used with high sensitivity horn speakers
and also have a limited lifespan, are more sensitive to vibration etc. but still many people stay with this technology regardless because of the quality of the sound.

Alex

I made a mid-quality vacuum tube amplifier in 1961. Its output tubes became unmatched after only a few months and needed to be replaced to have low distortion again. It happened over and over.
I replaced it with an H H Scott solid-state receiver in 1964 which still works perfectly today. Since its output power is fairly low (it has only 18W per channel) then it is not my main sound system anymore.

betwixt said:

I grew up on 6L6 amplifiers and 807 PA stages which shows how old I'm getting. Sadly, my junk box is now full of microprocessors not glass tubes.
Take a look at this though: YouTube - hand making vacuum tubes Part 1

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haha yes we are both showing our age.... my early 2m band (144MHz) radio had a 3/10 driving a twin triode 6/40 in the TX output.
6/40's were very common linear amplifier tubes way back then

During the 70's and 80's whilst working for a telecom company I had plenty of opportunity to pick up old valve radios in my service trips to customer homes to work on their phone system. It was amazing the old radio gear to be found stowed in attics and basements that could be often had for nothing but asking or for a fiver or so

The old Columbus radio receiver was one of my favourites to restore their wooden cases responded well to sanding and varnishing or staining. Ya gotta love that ol' mellow sound that is missing from modern sound gear.
I learnt tube technology at an early age from electronic and amateur radio Op'ers mentors.

Dave

I have a small collection of valve radio sets from various manufacturers, I appreciate valves very much.
I think they are fading away now though, they were popular in transmitters untill recently, there was even a very high power triode in a industrial induction welder where I used to work, if you own a car in the uk the exhaust system will have been seam welded with it.
Mosfets seem to be taking over, everything is about class E these days, except for microwave which seems to be popular with microscopic fets.
I keep the filaments lit now and again, and I have respect for those who appreciate such things, and where the PC sat on yor desk came from.

Some of the best sound recording equipment used tubes (and still do) and many of the greatest albums recorded where done with tube based equipment. Many of these still set the bench mark for how recorded music should sound.

Go into any top recording studio nowdays and you will find tube equipment being used on a regular basis. The Neumann U47 is still the most used vox mic in professional studios, the Fairchild the most sort after and unaffordable compressor, and if the budget allows Themionic Culture one of the first choices of top end new gear. All Tube.

You would also be hard put to find any pro guitarist using an amp that wasn't tube.

Anybody interested in the recording studios of the 50s and 60s might like to have a look at my site.

https://www.philsbook.com

philreno said:

Some of the best sound recording equipment used tubes (and still do) and many of the greatest albums recorded where done with tube based equipment. Many of these still set the bench mark for how recorded music should sound.
Go into any top recording studio nowdays and you will find tube equipment being used on a regular basis. The Neumann U47 is still the most used vox mic in professional studios, the Fairchild the most sort after and unaffordable compressor, and if the budget allows Themionic Culture one of the first choices of top end new gear. All Tube.
You would also be hard put to find any pro guitarist using an amp that wasn't tube.
Uk Recording Studios in the 50s and 60s

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Everything you said is simple truth. I'm guitarist and there's no serious gutarist who doesn't use tube amplifire. With Atarado boards I made few experiments, and there's nothin in audio compares to tubes. Such level of details and transparency with easy to get 3D sound....simply the best.

Your claimes about studio are 100% true, Hi-Fi in high end segment can't survive with tubes also. Tubes are simply superior over semiconductors in sound reproducing.

There is an ugly old lady in my neighbourhood who walks her old dog on my street every day. They are boring but are fine.
There is a pretty young lady who walks her young dog and they are extremely lively and attractive.
They both do the same thing but are very different.

The output transformer in a vacuum tube amplifier messes up the high frequency response and provides poor damping of resonances of the speaker. The transformer adds distortion especially at low frequencies. A semiconductor amplifier does not have an output transformer.