Glad it was helpful!

Ouch, yes, nice subject! ; )Thank you. There's no reason really behind those statements in such overly generalized (and as such meaningless) format, especially as it regards issues with feedback and transformers, and not the tube itself... It's kind of like saying it's harder to drive at night, that's why I travel by bus night and day. (Car being tubes, and bus being FETs).

@@realworldaudio Thanks so much for your answer! A video about transients would be very cool, it's an underdiscussed subject :)

I think it pretty much is, just like frequency extension, etc.

I have not heard any yet. I suspect they will be terrific for driving near-short loads, and we can have ever smaller speakers, and cheaper amplification. I do not fully understand the system, but apparently it uses a comparator technology against a triangle wave to keep the unit stable - not sure what sort of sonic signature that gives to the amp. I suspect your suspicion is correct, it can deliver amazing quantity at pretty decent quality, but not nearly the low detail, and harmonic detail level of a good tube amp. I assume that because of the gigantic headroom, it does not go into clipping as early, so there's much less HF distortion at normal listening levels.

Correct, there are many factors at play. The voltage acts only as the ultimate limiter, but other measures need to be taken care of to be able to use the potential. When same measures are observed, then doubling the voltage drastically increases dynamic resolution.

@@realworldaudio I liked your video generally, but this stuff relating operating voltage to resolution is just plain wrong. Just switching on a little BC547 involves 3,000,000,000,000,000/sec electrons passing through the base/emitter junction, never mind what's passing through the collector/emitter junction at nominal operating current (it's a MUCH higher figure still). This allows for a fineness of resolution miles beyond anything audible to us. If the operating voltage of analogue components materially limited the resolution of audio reproduction, line level (approx 1 volt) would be lousy and the voltage produced by a dynamic microphone (about 3 mV) would be unusable!

@@franciselers1534 Thank you for your comment! If your reasoning would be correct, then the electron microscopes would be operating on a 1.5V battery, and not on 300kV, and all audio gear would be running on 1.5V - much safer than 50V or higher, so if it would be possible that would be the only technology we need today! The speed of light is a constant, so that information is not relevant to dynamic resolution. If the speed of light was the determining factor of dynamic resolution, then there would be zero resolution as every electron moves at the same speed, so we would hear no fluctuations at all. The electrons are moved by the electron motive force, which is expressed in volts. The greater the motive force, the greater the momentum of the electrons to jump from one atom to the next, also expressed in electron volts (eV). While every subatomic particle travels in the vacuum at a speed close (often infinitesimally close) to the speed of light, only photons, neutrinos, and a few other particles travel at speed of light. The energy the electrons carry (and what makes them capable to escape from a grasp of an atomic nuclei) varies tremendously. A single electron literally can be carrying next to zero energy, never leaving the atom, or the energy to create a miniature supernova explosion upon impact. (0 eV versus 1 tera eV.) The range between the extremes of the electron motive force is the dynamic resolution: the electron either does nothing, or can do feats that seems like affecting a mountain proportionate to its size. For example, at the level of a LOMC cartridge the voltage peak is but 0.3mV, but there the range starts from pico volts. This range gets amplified by preamp and then by power amp ranging nano volts to 50 volts, or nanovolts to 600 volts.... matters a lot. Thank you for your thought-provoking comment!

@@franciselers1534so what your saying is you prefer transistors right? I think the point to this video was to explain it so someone without your obvious background in the topic could understand it .

Actually I wish I had the skill to reproduce the first hybrid automotive amps “Butler audio” made around 2000 because in my opinion this circuit really did give a tube sound with the power and reliability of transistors. I don’t know it to be fact but It’s my understanding that they used the tubes to regulate the rail voltage of the transistors . One of these days I’m going reverse engineer the one I have and draw a schematic of it.

It depends on the tube type. Usually just the old tubes (1930s and before) have globe versions, and about 99% of commercial tube amps use new tube models (1950s development and newer). The old tube types have much better linearity, the new ones have higher power but compromised linearity. Tube development (and audio development in general) went towards making things more compact and more economical, but also more compromised in linearity. When tube rolling, you have to roll tubes with same characters. For example, cannot swap in a globe 46 for a KT120.

@@realworldaudio Tq for the information. Very interesting, linearity.

@@M0D60 You are welcome!;

Simplified to the max: in a vacuum tube the amplification occurs in a vacuum, there's nothing obstructing the path of the electrons and they are guided / modulated by the magnetic field. In a semiconductor, the electrons have to bump from atom to atom in a glass that acts as a variable resistor. Difference is like traveling on an empty highway (tube), or passing through a city in rush hour traffic from red light to red light. All the rest follows from there.... Thank you for watching! ;

Good heavens! Hi Ed. All well, I trust?

It is a direct heated tube (DHT). There is no separate cathode, the filament is the cathode as well. So, the four connectors: filament 1 and 2, grid, anode. Such power tubes are: 10, 801, 45, 2A3, 50, 300B, PX25, 211.

@@realworldaudio all true, but an easier to understand explanation would be to separate the heater from the anode, as they do different functions. Though all tubes you mention are correct, the more common in this timeframe would be 6L6, and preamp tubes like 12aX7, etc with separate heaters. otherwise, good job, a lot of good detail not found elsewhere.

@@edevans4210 Thank you Ed! This technology was from an era when separate filament and cathode was not invented yet. Until late 1920s all vacuum tubes were direct heated, the first indirect heated commercial tube was the 27. Sadly, the direct heated tubes sound better than the more modern indirect heated ones, so the development went towards easier to build and not better sound. For this video, I used this tube as it has easy to see elements. Much harder to see on a 6L6, and the 12AX7 is perhaps too small to do a video on it... I should do a comparison video of different types of tubes, showing their internal elements.

It was quite a big step backward in quality, as far as natural human reproduction goes, delivery by presence, emotions and flesh and blood. Transistor tech was essential though to ramp costs down, and make it available for everyone “at the push of a button” - no need to be an expert and spend either tons of money or time…. Yet, as everything in life, the result is proportional to effort invested….

You have misinterpreted what I said. Yes, the cathode and the plate have resistance, the plate very high resistance, that is why we need the output transformer. However, these elements are NOT the substrates for the signal amplification: they provide the electron source and the electron acceptor electrodes. The signal amplification occurs in the vacuum, which lacks any resistance whatsoever, the electrons are accelerated without any particulate interference by the magnetic field generated by the cathode - plate voltage difference.

@@realworldaudio Well it still doesnt matter, the signal resolution is pretty much the same but tubes have higher frequency harmonics due to their construction which is called "tube sound". The cathode doesnt generate any magnetic field. The cathode gets heated and electrons shake out of their atomic bonds into the vacuum which gets them accelerated due to the high anode voltage, thus a current is formed. The vacuum doesnt really have resistance, but due to the distance it requires more voltage to attract more electrons, so you can view it as a sort of resistance, but the plate is the actual "resistive part" getting hot. the signal amplification happens due to the electrostatic field between the cathode and the grid, its the electric field, not the vacuum that does the amplification.

@@realworldaudio I recommend you read the RCA Tube recieving manual RC30, its free online as pdf, the first 100 pages contain a lot of knowledge about tubes

@@janno288 Thank you for your kind recommendation. I have studied that manual in depth, and also dozens more of receiving and transmitting tubes, rectifiers, VR tubes, etc, that I have in hard copies. I have a whole library on vacuum tubes, about 50 books, including vacuum tube manufacturing that describes details way beyond the RC30. Cheers.

​@@realworldaudio Very cool! I suppose you have gained more knowledge in the 2 years that followed after that video.