Building a Tube Amp! Does it produce better audio quality though? EB#47 

Yeah, i only have a high level understanding of tube amps, but every cheap circuit is still 80% silicon, the tube does nearly nothing. The parts that make a tube amp a tube amp are bulky and heavy, and pretty dangerous too. Like 400- 600v.

the problem with using tubes as final drive tubes is that it adds a ton of aliniarity the mentioned iron core transformer features a alinerar iron core which is a source of distortion add to that that those systems are rather inefficient and that they are only realy usefull for low powers and you have quite a lot of problems. also 0.1%thd is basicaly nothing in the world of silicon amps they usually run with a ton less untill they get out if their linear region. not saying that tube amps have to place to be quite the opposite if you find that mix of distortion pleasing to hear thats a great option for you same with guitar amps where that distortion makes a guitar spring to life. but just as a amplifier that has to create the most linear and accurate results tubes are not your friend

Tube sound superiority in hifi amplifiers is still a very contentious debate. There are many who believe that the amount of distortion is less important than the harmonic content of the distortion. The typical argument is that a strong 2nd harmonic is a pleasing "musical" distortion and tubes tend to distort in that way. It's a fine argument for guitar amps, but it kind of falls apart for audio amplifiers. Music usually contains complex a mix of frequencies and while a 2nd order harmonic might sound nice applied to a single note, with many simultaneous notes the resulting distortion products interact with each other in a very non-musical way creating a whole bunch of new frequencies not in the original piece of music. The result is a loss of definition of each individual instrument and a more noisy, veiled sound.

This.

Wait!! Let me get to the point. So her 80$ audio vacum tube are trash product that scam innocent peoples to buy it because humor about tube sounds quality? 🤔🤔🤔🤔🤭🤭🤭🤭

I don't think it is that, but it's easy to find out, i suggest you get a spectrum analyzer and check the output of the Valve amp, i was thinking in do that, but I don't have the time. As a tube amp designer I think this will be great to do such a test, who knows put to a end to this discussion and legend :)

@@luigicfilho Many have done such a test and verified exactly what Liam wrote. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UcNKGagfMyg.html

Electrons move more freely in a vacuum!!!

"Musicality" is a by product of distortion. Choosing the type of distortion, and it's amount of influence is the really difficult part of audio design.

Scott was looking at the wrong curves if he wanted to compare tubes with transistors. The curve that really gives the information is the one that relates input voltage to output current. For a tube, the current out is approximately proportional to the square of the voltage in. When the input receives a sine wave of a particular frequency, the output current will mainly be a sinewave of the same frequency plus a lower amplitude sinewave at twice the frequency. That's second harmonic distortion and, for some reason, our hearing perceives that as a pleasant sound. There will usually be small amounts of fourth harmonic distortion and higher, but still nothing we tend to find unpleasant. For a bipolar transistor, the current out is approximately proportional to an exponential function of the voltage in. When the input receives a sine wave of a particular frequency, the output current will mainly be a sinewave of the same frequency plus lower amplitude sinewaves at twice, three times, four times, etc. the frequency. That's still harmonic distortion, but our hearing generally perceives third order harmonics as unpleasant, and the same seems to be true for all odd order harmonics. Nevertheless, well-designed amplifier circuits incorporate generous amounts of negative feedback, which will reduce distortion (particularly in transistor amps) to levels that are virtually unmeasurable against the background noise. It is very difficult to believe that anybody could distinguish the difference between an output signal from a tube amp and that of a transistor amp if sufficiently high levels of negative feedback were present to ensure that the output was a faithful reproduction of the input signal. Oddly enough, field effect transistors have just the same sort of transfer characteristics as triode amplifiers, but we don't see audio enthusiasts complimenting the sound of jfet or mosfet amps. One of the other differences between solid state and tube amplifiers is that solid state clips signals quite abruptly when overdriven, which effectively turns a sine wave into a square wave, A square wave is equivalent to a sine wave plus its third, fifth, seventh, etc. harmonics, which are just the ones that we find unpleasant. Tube amps clip much more progressively, adding extra harmonics gradually as they begin to be overdriven, so that may account for the different "sound" of the distortion found under overloading conditions. Finally, the much higher voltages found in tube design allows more overhead before the output starts to stray from linearity, and the higher voltages and higher impedances of tube amps often require output transformers in order to match low impedance loads such as loudspeakers. Those transformers often restrict the frequency response and can introduce other nonlinearities into the amplification chain, and may themselves be significant contributors to the "valve sound".

Well, he meant well !

Thanks😁

Same here!

@@greatscottlab your intelligence is the what help me make 50% of my tools, I am a student I can't afford to buy then so thank you for intelligence, I used to live in dueschland and y'all are amazing keep being creative!😸👍

I might have caught the tingle of it being a newbie electrical engineering student

That'd be sick

It is on my to do list

Heck yeah dit or buy !

I can make it. Just using my phone

Can't wait :)

Yeah

Opa

@@sdffsdafdsfsdfsd only you people don't care but others do

Agreed

@@sdffsdafdsfsdfsd TRU LUL

Indeed, tubes handle clipping more "gracefully" than SS, and are therefore still in great demand for guitar amps.

I'm surprised at the number of Mr. Carlson fans there are here.

Now that guy knows EVERYTHING and can fix EVERYTHING, much respect.

@@JohnnyClavin Much more than you think

Bet their wives/gf's will not approve hehehehe

Yes

I totally agree with your grandfather. In the 70s into 80s I earned most of the money to finance university by repairing all kinds of common tube devices (TVs, radios, PA-, Guitar & Bass-Amps). They always had to be repaired, esp. the TVs, because of damaged transformers, tubes and capacitors (because of the high voltages of about 300-500V, up to 25.000 in TVs), exhausted tubes (burnout), etc. Switching to transistors and thyristors changed everything later. Today from time to time I still restore some old guitar- or bassamps (at the moment a 'HiFi Binson 40WB' Guitar-Amp and 'Echolette BS40' bass amp both from the early sixties )

And his diction is so precise and proper !

It's well created i must say

You are welcome😁

No it's not at all. It's extremely easy and straight forward.

Trying to understand this subject with the "tube" amp he used is a falsehood. His explanation might have been correct but the tube amp he used to base his facts on isn't a true tube amp.

tube amps are nonlinear circuits so an ac sweep wouldn't be very accurate

@@5d51e2gyU6JD All circuits are nonlinear outside of their frequency response. An AC sweep would be accurate and useful over the range of human hearing

@@liam1253 tube circuits are highly nonlinear in the human hearing range as well

@@5d51e2gyU6JD and how do you determine the range for which an amplifier is nonlinear? With an AC frequency sweep. You have a circular argument

So you are saying i can finally have a gf?

@@cake-lord yeah my friends single days will be over............cheers

I've been DIYing for a while now tbh

Wait..... DIY?

Now explain how!!!!!!

I can put it on my to do list :-)

Yes please

I Gonna wait for it AHHAHAHAH

Yes please

So true, I'll have made my system all tubes pre amp phono and power amps. I never go back to transistors. Only half conducters I have got is my cd player ( modified teac vrds10se) and dac. If you build it right without any compromise it will preform very well. I better listen to even harmonics from tubes then the distortion from a Class D transistor amp. Cheers

Is that a threat?

@@okashaarshad2371 GTA V quote.

only interesting and suggestive comments, not nonsense like yours

Sure✌

João Aleixo relax boy, this is a quote from gtav and it’s quite funny, for me atleast

Government: don't!!!!!

Actually it's not that hard to make a simple fusión reactor at home

@@gcr100 It's certainly not cheap either ;)

@@BertGrink yeah, but with patience you can get almost all the parts on industrial junkyards for cheap

DIY, definetly!

Then you learned nothing of fact, sorry to say.

Blue LEDs are cancer for my eyes

No it can't. You can sort of approximate tube sound in software (or DSP) over an extremely low distortion SS amp, but even the best algorithms aren't all that good at reproducing the effect of tubes. They are still the best at what they do. Moreover the low pass filter is kind of a cliché; a proper tube design won't significantly roll off the treble (although some will do it on purpose because some like the sound). And that particular roll off comes from the output transformer, not the tube. Remember tubes can easily handle RF range, so audio frequencies aren't much of a challenge. In a preamp buffer like this cheap device, there won't be any roll off.

the answer is yes, but no. You need more than a lowpass filter, but overlaying frequency distortion is easy to do.

Not really. The roll-off comes from the OPT which isn't there in a pre-amp. Besides that, it's not about "recreating the sound" (the sound is far more influenced by the speakers than the amp btw, unless we're talking about overdriven instruments), it's about building/owning the real thing. I'm pretty sure you can modify a Prius to behave exactly like a Cadillac, even make the inside look like one with VR glasses, but is it a Cadillac? *NO.*

Jonathan Brouillet If FR looks like a tube, if slew rates are the same, if speakers are connected identically, any other type of amplifier will sound exactly like tube driven. This is physics. Everything else is subjective, personal, placebo.

@@jonathanvanier what the hell are you even talk about? You should run along and let the adults in the room talk electronics. Typical "audiophile" responses, zero EE knowledge.

Not really a good tube description either, he's clearly a tube noob, wasn't even looking at the right tube characteristics (see other comments).

@@trevorhaddox6884 eh hmm... yes i know but everyone learns throughout their lives (including me) and I mentioned "good video about vacuum tubes" because he tried and showed up what he does wrong. For a beginner video is not as bad, he showed how triode works, and basic schematic of triode amplifier.

Its pretty simple, tube amps add lots of even order harmonics. Thats it. Thats the magic. To our ears those harmonics sound good

Meh. You can add a NFB circuit to both and still hear the difference...

Don't we all?

@@mthompson965 Sure.

Don’t forget Uncle Doug and D-Lab!

@@jimhibert ohh :( my mistake.. Yes! you are right!

Mr Carlson agree with that video.

If it's for hi fi audio reproduction, a well projected output transformer will have a flat response in the audible frequencies

class AB also have transformer

Or they don't and use big honking transmitter tubes that draw ridiculous filament current/banks of normal output tubes in parallel. It's called output transformerless or OTL.

are you serious?🤣tube amplifiers are much worse than transistor ones. you can find measurements of their parameters on audiosciencereview for example. measurement of noise, distortions, channels separation of tube amplifier are the worst of all other amplifiers

You must be an expert , no doubt about that ......Peter Quortrup would like to have a conversation with you ....he will be happy to learn from you .@@user-qi1cs3zg3n

@@user-qi1cs3zg3nMeasurements do not make music , some of the finest kit measures terribly.

@@user-qi1cs3zg3n there are 2 types of audiophiles, those that spend their time looking into measurements and parameters, and those that actually listen to music. I'll let you figure out which type is the true audiophile Andrew is referring to.

@@jonsnow7092 The main problem is that hearing differs from person to person. Trusting the ears of a stranger when choosing something is not very smart. This parameter is very subjective. In a blind test, "listening" audiophiles are unable to distinguish one amplifier from another. Measurements and parameters are much more objective. Manipulations about “two types” and that “those who look at the parameters do not listen to music” do not work for those people who love the scientific approach and critical thinking

Yup, output transformers are a big part of the sound signature of a tube amp. That's why, say, McIntosh uses output transformers even on their SS designs. And that's why a proper tube amp (or a proper tube preamp) would have been a much better choice than a "cheap opamp and Class-D module with a tube buffer" for this video...

Consumer: Analog sounds so much better! Also consumer: *uses bluetooth*

@@thewolfin I find aptx has a comparable quality to line in on my lgv30 with quad dac

tbh it can all be "fixed" using other circutry (like filters or even - god forbid - op amp chips)

@@boazcohen7992 and that opamp filters loads more then distortion. I use discrete opamps. They do not much with the original signal.

He's not using a true tube amp. BTW, I like both solid state and tube.

I assume this isn't a triode, but a pentode. The two 100kohm resistors are a voltage divider. The lower resistor should be decoupled. Pentodes need DC on one screen. If the screen is tied to the anode, it operates like a triode. Look at the datasheet of the EF86 pentode. It has application examples. Pdfs are available online. Pretty much the only signal pentode used in audio in the 1950s-60s.

@@grisflyt Exactly. In this way it operates in ultralinear mode, which is a strange choice for a preamp stage. Usually you'd like a nice triode like a 12AX7. Here they probably should just connect the plate to the screen and run it in triode mode; after all, this pretend device is supposed to give you "tube sound" on the cheap. Although with a tube buffer strapped on an opamp with a cheap Class-D module for the output, I'm not sure it's worth the trouble: NOT the recommended way to audition tube sound if you're curious about it!

@@jonathanvanier I doubt that. In ultralinear, you have negative feedback within the transformer. How much is dependent where you tap it, typically 34%, if I remember. This seems to be nothing more than a voltage divider. Since it's important that the screen gets ripple-free DC (ideally low impedance, there should be a capacitor. This amp is just riding on the tube trend. I don't really consider this a tube amp. It may still be a fine amplifier. Today's opamps are very good.

@@grisflyt I went back to the video and I was wrong, the screen/suppressor grid is indeed connected to DC on the circuit and not the plate, so it’s not running in ultralinear. Sorry about that. This begin said, ultralinear really just means that you feed a percentage of the plate’s output to the screen; a simple way to do so is, indeed, to use a tap on the transformer’s primary, but you can do it with a voltage divider just as well. It’s still called operating the tetrode in ultralinear mode. And of course, in a preamp stage you don’t normally have a transformer tap available (or if you use something like global feedback, you’d probably rather do it on the cathode anyway). But you’re right that it’s just a form of feedback. All this being said, I fully agree with you that this device is not a tube amp, in no shape or form.

Agree

Pretty much the worst possible example.

Fully share

Digital ready speakers need digital inputs don't they?🍄🧙‍♂️

Here come the tube lovers