Totally agree with you Paul. I’ve been using tube amplification for the past 6 years or so and it just sounds right to me. It’s hard to explain but let’s just say that it’s easy on the ears and my brain. But as with all components within the chain, there needs to be synergy. I can now say that I’ve nailed it to a point where I can say ‘Yes!’ Still haven’t tried the combo tubes and mosfets so the story or should I say quest (lol) continues. But right now.. happy me! Just for the record , I’m using a Line Magnetic 211ia amp. Tentlabs dac and Tannoy XT6 speakers Gain/ driver tubes are Siemens ECC83 / Tungsram ECC82. Peter

I like the soft sound of tubes (or valves as they're called over here), that's why I use one in a mic preamp that I made.

Missing from this video is that the tube that Paul held up is available from different manufacturers -- and they all will have different sound. So GG should experiment with different tubes (tube rolling), until he/she finds a set that provides the best sound. Note that often new tubes (manufactured recently) are not always the way to go. In the world of vacuum tubes, there exists "new old stock" (or nos). NOS tubes are old tubes (perhaps several decades old), but are as good as new (they have never been used). Some NOS tubes are plentiful, despite their age. Others will cost more, if their supply is comparatively low. Once a particular NOS tube's supply is exhausted, then that is it for that tube -- as NOS tubes, by definition, are no longer manufactured. Whoever has them for sale, when their supply runs out, then that is it.

Right on Paul. I do hear lot's of tube amps that are poorly implemented and sacrifice resolution. Typically the issue is with the power tube coupled to a poor quality output transformer. I use all triode amplification but with OTL output stage. It has micro details unmatched by most other systems. It's biggest limitation is the quality of coupling capacitors which can also be upgraded.

I made a class A single ended tube preamp and impedance matched it to a good decent D amplifier, and wow. Holy crap, rest was history.. Massive wall to wall soundstage, holographic depth. and a detail and clarity in sound i've never experienced before. While yes, also being softer and easier on the ears as well. If tube pre and class D power is this good together, i can only imagine how good the BHK amps sound.

Once again, Paul, you've come up with an excellent analogy with the orange flavor. Thanks!

Good description, Paul. I build tube guitar amps and we intentionally modify the gain structure and frequency response to "improve" the sound of an electric guitar. A triode voltage amp is a high impedance stage and so the coupling caps are much smaller than a solid state lower impedance voltage amp. I suspect that the smaller caps (I use polypropylene) slow down the transient response far less than using electrolytic caps in the solid state voltage amps. Thus, more details. BTW I use a 60s Harman-Kardon Citation V to listen to music.

When vacuum tubes are good, they are rally good. When they are not, well... then they are ''fatter, warmer and generally softer". As Pol said, hybrid settings are probably the best solution ... for perfectionists. For us ordinary mortals: a good solid state or a good vacuum tube system is... Hurray!

I like the sound in tube preamp and solid state power amp.

I don't know if actually affects resolution but it's definitely adding things like 2nd order harmonic distortion.

I had an Audio Research tube amp -- at first, it was quite beguiling . . . however, when it came time to replace the tubes at a great expense, I went back to my solid state amp . . . and was surprised at how different the sound was. The warmth was “too sweet”, soft, and the detail definition was lacking in the tubes as compared to the solid state. Sorry . . . it is a matter of preference, taste, and opinion, but in this one . . . I agree with the lady! I could care less about the measurements as a whole -- if my ears find the sound offensive, with distortion, and fatiguing to listen to -- I will trust my ears comparing the music to live any day to people's opinions. Hey, I have to pay for and listen to what I purchased -- and it is going to be pleasing to my ears -- or it is not staying in the system very long.

"IF YOU TOUCH IT TOO MUCH YOUR OILS WILL BURN A HOLE IN THE ENVELOPE" uhhh, if you touch a hot 12ax7 too much, it may burn a hole in your hand , but will not affect the envelope. now, an 813, running at 1500v on the plate probably wouldn't like any hand goo on the glass , but i doubt it would burn a hole in it.

You hit the nail on the head... your goal is to make it sound as close to live as possible, not as close to the recording as possible. That explains a lot. So really the most important thing to making it sound as live as possible is how it is recorded, mixed and mastered. How it is played back is second to that. If it was recorded badly it will never sound like the live instruments. What if there never was a 'Live' instrument... for example a song created exclusively on a computer?

I believe that accuracy is something to strive for. Many manufacturers use valves to add qualities to the signal that are pleasing. Some add sparkle, some add a warmth and so on. There are ways to employ valves that makes accurate sound e.g. as voltage amplifiers in microphone preamplifiers. They have high resolution and good harmonic discrimination. When used correctly they produce playback that is accurate and compelling. You can see valves in cheap products creating a visual aesthetic and subtly messing up the accuracy to let you know they are there. Or else there are high end uses that make compelling sound that is appealing. I guess I am saying that you can use valves to modify a signal or you can use it as a useful tool for perfect amplification.

For a man that doesn't really use tubes I really appreciate your honesty...

I have heard new tubes don't sound as good as old tubes. Tubes in general just sound like a never ending struggle.

I had a small tube amp and it was bright but no fatigue what so ever. Sounded so sweet up top, and turning the treble knob right up made it sound way wrong and tinkly by a large measure! But it was so sweet and sounded great even when the treble was floored and heaps too much treble. The best treble from any amp I owned. I own a big NAD and an Audiolab 6000A. That little amp would have smoked both, only if I still had it. I also had other tube amps too, but none as good as that little beast. UNFORTUNEATELY I sold it in the mid '80s. I failed miserably!

Vacuum tubes certainly do have their issues. They are much larger than their solid state counterparts. Like a incandescent light bulb, they waste oh so much energy in heating the filaments. The circuit layout must accommodate that heat in a way that it can dissipate without harming other components. And, compared to solid state components, they are noisy. Not only are they noisy, as in distortion. But, they can be terribly microphonic. However, in some applications they are ubiquitous. While searching for a guitar amplifier that could fulfill my needs, I went with a 1968 Fender Bassman. It is heavy. It produces a lot of heat. But, in this application, I don't believe I could have spent my money more wisely. It is wonderfully simple to modify, or repair compared to modern printed circuit board amplifiers. But, best of all, it's so expressive that I can simply vary my pick attack and change the character of the sound produced. You simply cannot get that quality with transistors.

Couldn't agree more. A tube on the input stage puts flesh on the bones.

Great Video & Much Love 2 All.... Keep Those Tubes Glowing !!

I have done all vacuum, all SS, combo of both. Combination of the two is the best to my ears. The Rogue Sphinx is one of the best piece of equipment I've purchased in the last ten years. I agree with Paul on a previous spot he did, tubes at the input and SS on the output is truly great.

The still picture is not a high-fi amplification tube, but rather a nixie tube, which is used for displaying numbers.

the design can also change the sound of the tube amplifier. e.g. OTL or transformer-coupled

Under ALL situations... tune your room to your speakers. I'm running a Carver 1.0t amp and even a cheap Noobsound preamp using audiophile tubes on my Infinity's and it's astoundingly powerful and the imaging is better than you'd imagine in my listening room. (advice given to me years ago and the absolute best thing you can do in your listening area and best money spent after one owns their decent equipment) **honestly...** Thanks Paul for these videos my friend... YOU, Sir are the best. :)

If you take a good look at schematics of Tektronix and HP oscilloscopes of the 60's and early 70's you will see some of the best engineering ever. I used to do calibration of all the test equipment where I worked and that included repairing all the equipment. One thing became apparent was vacuum tubes in a properly designed circuit are reliable, replacing tubes in the 545 (30 mhz time delayed) scopes was rare enough to be notable AND they helped heat chilly chilly corner where my bench was. I used to have tube power amps (Dyna st70 and then Jolida 502), I gave up on them when the cost of output tubes got stupid. Today I have a Rogue RP5 tube preamp driving a pair of M700 monoblocks (class D all solid state) and I can tell you that combination resolves just fine.

Orange zest in orange juice sounds great. But all oranges are not alike. Sometimes when the orange is near perfect, I would leave the zest out. All tube amps, and ss amps are not equal, so I think some ss amps sound better than some tube amps. I enjoy my Scott 20 watt push pull el84 amp with high efficiency JBL 15in speakers because it sounds very good and is somewhat affordable. If I had a lot of money, $2m, to burn, I'm not sure I would be satisfied or happier with all the confusion of who or what is better. I am happy listening to any very good, or even good hifi. I also find old 78's enjoyable. It's about the music, and I do enjoy the historic overtones of different eras even though it is not as deep of bandwidth, 3d?, Imaging, dynamic, and on and on... I do enjoy the videos, but when Paul describes a macintosh stereo as dad's hifi, it's a little too condescending and I think narrow minded. Maybe I am a little defensive of not having $2-3m to spend on a music replicator, but I do recommend live music when possible. To me there is nothing like the low note on a concert grand Steinway or any good concert.

I am a recent convert, tubes in, mosfets out, just sounds natural to me

No matter what one does to "fix" orignal source digital", it just doesn't sound very good to me. But, if I want to really listen to music, I have to use headphones, for my my living situation. I like original analoge, mixed & mastered digitally. Preferably HDCD, for I can make custom playlists on Mediaplayer, and hear it at double the resolution of a basic CD. An overall good compromise for me. Custom playlists are very essential for me.

Thats a 12AX7 isn't it ? Got a huge collection of NOS for guitar amps.

Tubes in gain stages don't affect clarity or so-called "resolution" as long as the circuit around them is competently designed -- but tubes in a power amp's output section entail inductive coupling (an output transformer) in order to drive loudspeakers and a big iron core can't help but be at least somewhat detrimental in that regard.

I love all tube power and preamp lots of clean organic headroom its like your there of what your listing to and my bass guitar amp Ampeg svt cl 300watt all tube and it is sounds so so so good ive got preamp with mosphet section amps to its not even close

Tubes might not be ideal for certain DACs. I think that’s why some people recommend them for analogue sources like vinyl players. They make distortion sound pleasing. Tubes are wasted on high performing DACs; they are fine on noisy DACs.

So then VTL is wrong for using tubes in both pre and amplification sections ?

Paul, why no elaboration on hotter vs colder biasing, and what it means for the sound. Or open loop gain for that matter, or sag, or transformer saturation. Those are the main factors that determine the specific sound of a tube-amp. You know, basically finely tuned distortion ? Resolution sounds kind of... like undefinable hot air, wouldn't you agree ? ;)

The lore that tubes sound warm, I think, has to do with the type of vintage speakers they were typically player on.

To Poul - are you going to use the Korg Nutubes ?

I guess it has to do with how well a tube compresses louder signals. Unlike a solid state amp, which hardclips, once the audio wave surpasses the limit, a tube amp, just gradually compresses the signal. The higher the signal, the higher the voltage, the more of the audio signal will be compressed due to the higher voltage being transformed into light. Nowadays they have transistor bulbs. A bulb emulation with the use of several small transistors, in the shape of a bulb. It seems to work quite well! American company as well! But sometimes, bulbs do remove higher frequencies, due to the addition of hiss; and over-pronunciation of mid-frequencies. So yes, most budget tube amps have this problem.

Had Heathkit mono amps with a Heathkit stereo preamp , miss that sound. Class D, yuk!

It's sad to hear that my tubeless psaudio gcd preamp sounds over-edged and unnaturally. :'(

I have a dac that has a tube preamp built into it. There are two rca outs, one for tube out and one for "solid state" out. I much prefer the solid state output of the dac, sounds much more sharp and fuller to my ears. Listening to tube out is like seeing/watching something without eyeglasses on for me (I have -2.0 prescription). I have WE 396A and GE 5670W tubes on hand and neither sounds good to me compared to solid state.

If you say tubes ware out, then the sound is slowly getting worse as you use it

Tubes are actually a passport to Heaven!

What you are saying is probably true for triodes, but what about using beam power tubes (pentodes) for greater output efficiency. Power triodes exist, but who except fanatics want them? So tubes in the pre-amp stages are great, but go with transistors after that.

3:00 do not worry

I think the term you're looking for is like an oscillation of a wine glass, when you run your finger around the rim of a wine glass a sharp clarity and detail sound. I thought maybe you could use light bulbs in the same way on the output transistors to regulate themselves and give a Walmer feeling. I don't know if anybody has done this?

The perfect amplifier is when the sound that comes in is similar to the sound that comes out of an amplifier. The sound should not be colored. Comparing with earphones, the audio output of a CD player should be equal to the sound out of the speaker output of an amplifier.

This is why many lovers in audio ended in last years. Why so many people are here so toxic? This man gives you information for free. This is sad

Everything has distortion, everything has headroom; opamps, transistors, tubes etc it's all about designing circuits to keep the positives and minimise the negatives. Also this is about the preamp stage when it comes to current amplification (the stuff that makes it loud) tubes can't compete for efficiency.

I saw paper put inside the open pre-amp that cause huge ESD concerns, especially MOSFETs are highly ESD sensitive devices.

I guess you use with tubes a LTP config with BJT or FET currensource at the bottom in a feedback topology? Or open-loop?

Paul, just so you know, fingerprint oils burning a hole in the glass is just superstition. I mean, fingerprints are unsightly and you typically don't want to see them on your brand new expensive tubes, but they are not going to cause a premature death.

What make of audio tube do you use in you're Pre amps ???

For me a pre amp or buffer stage made with discrete transistors running class A sound better than Tubes

Is there a reason why mosfets cant be the size of credit cards wrapped in its own heat sink and plugged into sockets on top of an amplifier.Heat sinks can come in gold,silver or black even.

Hey Paul, what do you think of pc programs or plug-ins that emulate the sound of tubes in windows players? are they reasonable?

First time i'm suspicious about his explanation... Tubes distort the sound right? So how can they be accurate?

Paul, where is the chicken award for this? You really got those cluckers clucking with this one.

Paul: I've been wondering about a certain combination "Tube DAC" and solid state amplifier known as the Aune T1. It is said that the vacuum tube is part of a buffer leading out from the DAC into the amp. Is this a good application for a tube in such a case? Is it in essence using the tube as an input into the amp?

Now I am confused. I run a Leben RS-100 pre amplifier with tubes and a Nord Acoustics Nord One SE Hypex NC500 (Class D) power amp. Don’t ruin it for me, I am quite happy with the sound and powers my Tannoys just great. ;-)

A friend of my Dad gave me a Harmon Kardon Citation 2 tube amp, I love it. I would not say it is better or worse than my Solid State gear, but it sounds great and is damn sure cool! I need to replace the tubes, and the capacitors, but I cannot afford to do it right now. I do have a question for output tubes, which is better, the KT88 or the 6550? It had 6550's when I got it.

If so. Why don’t you use tubes in your DACs output stage?

Overly edged edge... That's the explanation of a Hegel class D amp on a pair of B&W speakers with harsh tweeters. I've heard that combination at a local audio store, it was terrible. After that, a class A Esoteric amplifier driving a pair of Sonus-Faber loudspeakers gave me goosebumps all over my body! I Am a tube lover, but the Esoteric beats them!

No!! in fact they have increased resolution over BJT transistors.

Tubes are certainly not going to be as "transparent" as a well built transistor, all things at highest quality; and they will degrade, progressively changing the sound (which you brain will normalize to till it is too much). But a bit of analog softening is likely something the human ear would favor in high fidelity sound when used right. As the brits say: "horses for courses", as in, if you want a clinical sound with no artifacts then go for something that adds nothing and it (a good transistor) will do that (arguably), but if you want something that won't cause fatigue and won't hard clip, then a tube is good. I'd probably prefer whatever was being modified in the sound be done at the creative stage, not the playback stage. I want to hear what the artist intended. Even tonal adjustments after the fact are more about balancing a room or compensating for whatever sound the drivers introduce. A tube will change something. but in the end it really is a matter of preference... So there is, as always, no right way.

I had the exact question in mind with my tube headphone amplifier. Thanks for clearing it up Paul!

Tubes can be made to sound soft. That does not mean tubes sound soft. The myth about the soft tube sound stems from older design concepts. Tubes can be lightning fast depending on how and where they implemented.

If the goal is Hi Fi (fidelity), then why choose to add any color which is not in the original audio signals even that add color/distortion sounds good to some human ears? That coloration is "fixed" given certain tubes applied. Instead you could go DSP route which give you a world of possibility to create any add-on sound color or effect you want to try or like. That shall be the real HIFI and audio art route to go!

What does it matter if you are wearing hearing aids.

Paul is struggling to explain because he's making tube amp too.

I'm sure Nixie tubes will effect your resolution lol

Bandwidth is bandwidth. A 12AX7A can be used well into the Megahertz range. So can a bipolar or FET t ransistor. In an actual real world preamplifier system, a 12AX7A tube is very hard pressed to reach a flat bandwidth of 15 KHz despite that. But many transistor amps are capable of flat audio bandwidth of nearly DC to several hundred kilohertz. NO WAY that tubes can have the resolution of solid state under those circumstances. As for the notion that tubes sound better...yeah, if you like the sound of added harmonic distortion. If that sounds better to you then it sounds better...to you. I do use an Audio Research LS2 line stage with one tube in it. I can't actually hear that it sounds appreciably different compared to my other preamp, which is a 1987 vintage Pioneer Elite C90 preamp. The C90 is very complex with lots of inputs and loop functions and the LS2 is very simple. I'd be hard pressed to tell you which one I'm hearing if you were to swap them around and not tell me which one is actually hooked up.

vacuum tubes or valves for you europeans are not halogen bulbs so fingerprints wont compromise them. you used a nixie tube for the thumbnail although they may work as an amplifier tube if you was building a crude circuit like those who used vfd displays as amplifier tubes

The sorriest tube equipment blows away the best transistor e quipment.

yep

My Wife and I were sitting on the sofa in the living room the other day. I had Allan Parsons "Sirus" flacs playing through a class D amp in my theater room. She turned to me and said is someone at the door? I listened, No I dont think so. There... what was that she said. Oh, that is the part of the music you never heard before i said with a smile. Its a great feeling to see someone else "Get it"" for the first time.

YES

The bit about the overly sharpened signal was exactly the case in old crt televisions. They had a "feature" (I'm not even kidding) where they would mess with the scan velocity around the edges of the items in the image to "sharpen it up". It was called scan velocity modulation (SVM) It just served to put halos around everything and it sucked massive donkey testicles.

All depends on the tube, circuit and implementation.

For ultimate resolution and transparency and lack of coloration, I also suggest AR REF 6 Pre & AR GS150 power with say, Siltech 770L series cables. All tube gear.

Explain why tube computers so muching slower than solid states using the same circuit? The difference is the switching speed across the junctions. Hence the softness (delay response) with tubes.

I think this whole line of thought dates back to the early days of transistors in the 1960's. The early transistor equipment was terrible. Can you think of any transistor collector gear from the 1960's? We had sunk into the abyss of newest-latest-greatest when a man named William Zane Johnson started a little company called Audio Research in 1970. www.stereophile.com/interviews/894z/index.html He was basically alone until Dr.s Bill Conrad and Lewis Johnson started conrad-johnson in 1977. This was the same time period when every other audio company was vying for the most vanishingly low distortion numbers, usually through more and more negative feedback, and the result was vanishingly low musicality. Yes, the renaissance of tube gear sounded lush and "soft", but look what it was being compared to. The early days of digital was a reboot of the same scenario, hard and edgy equaled better sound. "Perfect sound forever" was the selling point. It is not true now and was not true then. In case you think I am anti-digital, yes I used to be. The modern DACs however are quite good, and mine has tubes. This is not to say that all transistor gear was bad. Nelson Pass was making some stunning equipment with his company, Threshold, beginning in 1974. I always liked Spectral although I thought it's sound was grainy. And, perhaps the best amplifier I have ever heard, the Mark Levinson, John Curl designed, ML-2 came out in 1977. Now that I think about it, the post Audio Research high end transistor gear was really quite good. Did Mr. Johnson start something? Paul's answer is spot on. Tubes can be good or bad, as can transistors, as can hybrids. After all, it's not the wand, it's the magic you work with it.

name change? i almost got confused lol

I sent in a question weeks ago. Do some of them not get read out or is there a backlog?

Sure, in the sense that tubes are distinctly nonlinear devices and always introduce some distortion. Otherwise? No. That's nonsense.

Heard the best thing that can happen to tube, is that some one invents high ohm speaker. Then You can avoid the transformer.

Bloody hell these amps next to you look sick!

Great video and a marvelous explanation.

Tubes work best in preamps. Its the transformers on tube amps that cause a loss of resolution. I have also heard a tube preamp that was soft. But that was a design choice. On the other hand, tube amps normally require output transformers. My tube preamp is a hybrid, and it has just enough "niceness" to make you smile.

Tubes don't reduce resolution -- but output transformers sure do, and tubes require them to drive speakers!

That super sound stage is not there with Class D , all that compression for font end . I have never had a tube amp , I bet all the atmosphere is there . Should give my speakers a Full Test in sound quality , and my ears too !

I have a vincent audio sv-236 hybrid integrated this amp sounds as good and sometimes better than my previous much more expensive Sim Audio w5 and matching pre amp.

If a class D amp is your reference....

Yes, another video on tubes! For people suspicious of them - tubes and or software "plug ins" designed to add distortion & warmth are used ubiquitously in recording music. A lot of your music is already "pre-tubed" lol.

The great thing about Class D's ability to reproduce the source material with such fidelity is that if you have a piece of equipment that runs tubes, the receiver and power-amp will not "detube-ify" the sound. If you want the sound of tubes, what I've come across in my travels is an old Yamaha tube preamp/compressor. It adds all of the tube magic, while still allowing all of the solid-state/digital equipment in my setup to breathe, so long as the compressor is set wide-open. Compression sounds great with certain guitar tones and with drums, but for Hi-Fi... Not so much... But that's okay. I just bypass the compression circuit and Bob's your Auntie.

Vacuum tubes reveal inner detail of notes and transistors are better at out lining notes. both high light different aspects of the signal. think attack vs. decay on a piano note, or a note struck by say Neil Young on the Guitar.

You do realize that the tubes in the thumbnail are Nixie tubes, right?

Tubes are far away to a perfect linear in to out transmission of the original soundquality. They often sound "bigger than live" but when it comes to a longer listening experience, I dont like any coloration of the original soundquality. Tubes are great for guitars etc. but highend means to me: absolute high performance.

Tubes belong in guitar amps.

What, exactly, is the definition of "audio resolution"?! Too much bs in the audio world and not enough real engineers.

That stuff about your "oils burning a hole in the envelope" is pure horse-shit. This is a myth that came out of the pro/stage lighting field, where a fingerprint on the surface of a quartz-halogen lighting element will indeed cause it to fail, often explosively. NO audio tube runs anywhere near hot enough to fail in this fashion - period. I'm a US Navy-trained tech with nearly 60 years experience, all of it on vacuum tubes. Most audio tubes wouldn't care if you dipped 'em in squirrel-shit and painted 'em green - they'd still work just fine. All those audiophools you see/hear admonishing people to wear white gloves when handling vacuum tubes is pure bunk and tomfoolery. And that stuff about tubes wearing out in a year is also nonsense - I've encountered tubes in guitar amps that still tested perfect after 50 years, and sounded great.