I'm almost 55 years old and have an electrical engineering background, I must say that this is an excellent layman's explanation of how an amplifier works! Well done!
@@aidanduncan8187 For whatever it's worth, I'm completey baked rn watching this and I think our highnesses seem to cancel each other out so it sounds normal 😁
I am 73 years old and a Nurse, a computer technician and was a mathematician before becoming a nurse. This for me was very insightful as I have started working with pre-amp tubes for audio. I particularly like what you said as to a benefit of tubes over transistors. Thank you for taking your time and sharing!
I've been playing Tube Amps for decades and never worried about how they worked, kinda like a race car driver that never worked on engines before, just drove he shit out of them. Hey it worked for years. But now, with this easy to understand explanation of what goes on, I found myself selecting tubes to produce desired tones from my amps. Let alone doing work inside the heads a lot more safer than any other times before. Thank you sir, good job.
I found that learning how to build guitars gave me the same benefit that working on cars gave me, discernment on buying them!! If you know how a guitar or engine works, then you can know what is wrong, could go wrong or is lacking in them.
I'm about to build my first tube amplifier! I watched this video because I'm just so excited about what I've been learning from my teacher. Everything you say adds up to what he's been saying, and he's a veteran tube guy from back before transistors were cool. Nice job man.
Yes it's quite neat to watch isn't it? There's a video on youtube just filming the tubes of a 1000 watt amp on full, playing Charles Marie Widor's 5th symphony. It's really mesmerizing to watch.
Beta radiation. Good thing it gets stopped by the glass envelope. The glow comes from electrons passing through holes in the plate, originating from the cathode, and striking the glass with enough force to emit blue light.
Wow! You did a great job of explaining the tube amp operation for someone who does not know electronics. I have been an electrical engineer for 40 years, and a guitar player for 50 years! I really enjoyed your video. Take care, Sparky
You, Sir, have my respect. I've worked as a science communicator for many years, translating highly complex material into engaging stories people can relate to. I'm a total noob to everything relating to electric guitar playing, and my pre-existing electronics knowledge is almost non-existent. Of course I had learned about tubes in school, and I knew they're essentially tiny old-school TV sets (the "ray gun" kind), but how such a thing could possibly make a guitar sound was completely beyond me. Your explanations cleared that up beautifully. Very nice work!
This was easily the best explanation I've seen on youtube. An interesting idea I have on building my own amp is to use Lithium phosphate batteries to run the amp off of DC Current. that way you always get nice clean direct power. I think you could still plug the guitar amp into the wall, but it would just charge the batteries. Its like have one giant capacity, with the benefit of making your amp portable too like for busking.
Thanks for all that ! Many years ago, Dutch company Philips, sold as Norelco in the States, used tubes in their radios but had trouble with output transformers, so they made a special range of 700 ohm speakers for some of their sets !
This information is not entirely accurate. Philips had no troubles with output transformers in their tubes radios. At that time, Philips used no output transformers for other reasons: first, to achieve a better sound quality and -also important - reducing costs. The impedance of the speakers when used were 800 ohms
Been messing around with amps for a while, thank god for my high school robotics club or I would be spending 1500+ dollars on tools. This helped a lot! I've had a lot of failed projects but I recently built my first working solid-state amp, and its an absolute mess. But hey, it works. I'll try to fix it tomorrow since I blew it out upon plugging it in today. Its the small victories I suppose. I have a work in progress tube amp as well, so thanks!
At first I thought this would be terrible but it turned out to completely blow my mind both with how I learned how cool it is how tubes amplify sound and how fast I learned it. Incredible job explaining this, never would have been able to understand it better.
Great walk through and explanation of parts in a amp. I always wanted a more in depth video how it all works because it gives you more knowledge when looking for an amp. Well done mate keep pumping these tutorials out... its appreciated!
Many thanks, Brandon. As a noob, I appreciate someone who doesn't assume the view know ANYTHING about amps............That's where many knowledgeable instructors fall short.
Thanks for the explanation. Recently had tube amp problems in my EVH 50wt. After a simple tube replacement did the trick, I needed to know how it all worked. Got a slow start at 57
Good video Brandon. A couple comments. Line voltage is measured RMS, not peak. Unless otherwise stated, AC voltages are RMS. The grid in a triode is commonly referred to as the control grid. The screen grid is the 2nd grid in a tetrode. The surpressor grid is the 3rd grid in a pentode. Keep up the good work.
I just learnt so much from this and I’m not a guitarist or actual music person at all. I’m purely a listener and want to get into vinyl and turntables. That’s everything I wanted to know. Thanks so much mate
Glad you liked it! I use the Bravo Audio Ocean for listening. It's a tube headphone amp / preamp that uses a single 12au7. It's a wonderful little amp if that's something you're looking for.
This was great bro. Good job. I was just wondering how exactly a tube amp worked and what the tubes actually did and how they worked and u deff made it easy to understand. Thank for taking the time to do this and answer the question most guitar players wonder about and for doing it so simply. Appreciate u bro!
How to get around the vol of power amp clipping? Do what pros have done since the beginning... and continue to do, turn your amp vol to 7-10 (where ever your sweet spot is) use the guitar vol at that point. from 2-7 whatever the occasion calls for
Very informative video. Thanks for uploading. I've been compiling components to build my own version of the Dar Fbm 100w head since they're oh so very rare. You explained things in a way that is much more understandable than most blogs/discussions I've read.
(Being an engineer I thought I would just correct one item). When discussing AC and DC voltages you drew a waveform for 115V and said the peaks are at those voltages. That is not the case. The heating power from a 115v DC is equivalent to that of 115v AC. That 115V is an RMS value ( root mean square). The actual peak to peak voltage of the AC wave is 325V. To find the RMS value of a sinusoidal waveform- keeping it simple- divide peak to peak by two and multiply by 0.707. This is to give the equivalent power of the DC voltage. Keep up the good work.
Thank you for your comment, you are correct. I misspoke in the video, as the 120v in the US is the RMS value but peak value is around + or - 170v. I thought I added this to the video annotations because someone else mentioned this in the comments but it appears I did not. I will add it now!
Hey, way to go with a top level overview of tube operation with a touch of theory. While I was watching, I thought about referring you to Uncle Doug for a more in depth explanation, then you mentioned him as well! :-D Keep studying, and never stop learning!
His `` explanation``was very clear....the only problem is that it was factually incorrect which is a sure way to create myth and it can be quite laughable to anyone who is any way familiar with the trem ``boils``.....as anyone with any type of common sense know that to boil anything requires a liquid..It`s to bad that Brandon knowingly ignores the facts preferring to badmouth anyone who is trying to help him with cold hard facts.He gets offended when corrected and berates anyone who presents facts to him ....I assuming that in some cases ignorance is bliss...
Thanks for the video Brandon, it was very informative. Not many people can explain engineering/electrical designs as articulately as you have. Your video has broadened my understanding of tube amps. Keep up the good work!
Nice video Brandon. Hats off, awesome introductory materials!! I am from a solid-state transistor background, but I guess tubes work similarly, so i may be wrong. My little additional comment: each "terminal" of a tube has to be correctly "biased" at certain DC voltages in order to function well, and the tube only amplifies the "small" AC signals oscillating around that DC bias voltage.
Thank you! I am not as familiar with transistors (I am learning!) but that sounds mostly correct. Tubes have to be biased, but not each "terminal". The bias voltage also sometimes called the HT (high tension) or B+ (battery positive) voltage is "biased" or set between the cathode, anode, and grid. Depending on the type of tube this is usually between 300v - 500v in guitar amplifiers. When adjusting the bias, you are changing the amount of idle current flowing from cathode to anode (some current flows even when there is no audio signal). And yes you are correct, the AC oscillations from the audio signal applied to the grid modulate the DC bias voltage to replicate that signal. This amplifies it by simply "copying" it with a much larger voltage. You have to be careful with tubes though! Setting the bias too high can let too much current through, causing "redplating" where the anode heats up and glows red-hot. This can cause noise, arcing, tube failure, and amp damage. And biasing too low will result in poor sound quality, low efficiency, and possible strain on the circuit. Sorry for the long post! But in summary, yes tubes and transistors work on very similar principals, the difference being transistors operate on much lower voltages and are more reliable and efficient.
In your reply to Wei Huang, you are confusing B+ with bias. B+ is the positive high voltage supplying current to the tubes, while bias is the negative voltage applied to their control grids to control the amount of current flowing through them when no signal is present. In an amp with a bias adjustment, the cathodes of the output tubes are connected to ground, and a separate negative bias supply is connected to the grids. It is the voltage from this supply that you are adjusting. Making this voltage more negative reduces the current in the tube, while making it less negative decreases the current.
well that was an awesome tutorial, I know more now than i did before watching, I've got the same amplifier so it was cool learning what all that stuff back there really was,Thank You..
very well explained. And the question i had in mind for a long time for which i could not find any answer has been answered. Why exactly Tube amps sound different than transistor? Its the way the AC signal is clipped, transistor clips so that the peaks are flat and valve clips it, tthe signal is slightly curved at the peaks
Well yes, that's part of the reason. There are a number of factors as to why tube and solid state amps sound different. One main reason being that tube amps have an output transformer, which tends to "smooth out" the waveform.
@@metaldownm well the filter capacitors help convert AC to DC by smoothing out any ripple. But this is not part of the signal chain. When I said that the output transformer "smooths out" the signal I don't mean it in the same way that capacitors do. The OT kind of rounds off the signal before it gets to the speakers, whereas solid state amps don't have output transformers. Therefore they generally have a harsher sound. If you want to learn more, look up the Peavey White Papers. They have a lot of great info and one of the papers talks specifically about the output transformer.
WOW !!!!!!!!!!!!! VERY imformative video , i used to play the guitar if you could call it that . more like a hack , but i was looking for videos on tube amps for my home theater ... im sure they work on the same principle AWESOME JOB DUDE !!!!!!!!!!!
Its great for a young lad to learn all this stuff.. most of them these days are assholes that steal cars and destroy peoples property.. Brandon you done great i really liked your video.. ive learnt something today, i look forward for more !
Not too long at all, thanks. Yes, how the ear perceives has a lot to do with it also. When the signal from the guitar is slightly too strong there's a compression, in a sense, out of which other waveforms can arise. And, I don't know, like interference patterns and such. When one turns the volume on the guitar up, one is not so much turning something up as decreasing the resistance. This allows a more powerful signal from the pick-ups/strings. It seems to me like some guitars (basses included) are intentionally designed to have that little range at the top of the volume setting that allows overdrive. This gives the player greater flexibility of sound-- and more fun :D
Absolutely right! The reason for that little "boost" on some instruments is actually because there are different types of potentiometers. There are linear pots and logarithmic (aka audio) pots. With a linear pot the knob on 5 will have 50% output, 7 will be 70%, 10 will be 100% etc. But on a log pot the knob on 3 might only be 20% output, 5 would be 35%, and then this usually start to change rapidly around 7 or 8 on the knob which gives you that "boost". So at 8 you may actually be getting 90% output. I just made these numbers up as an example, but it gives you the general idea of the logarithmic resistance curve. The reason these are called audio pots is because they are used as the volume knob on audio devices like amplifiers. Human hearing is not linear so these pots actually trick our brain into perceiving the volume change much more smoothly. However on guitar I much prefer linear pots on the volume knob. I find them much easier to use while playing in terms of controlling dynamics and tone.
What a great video! It came up when I searched for the magic of tube amplification. It’s definitely a mix of science and magic that can really only be experienced by playing good guitars through them... where’d you disappear to BD? Good job.
