I’ve recently found a great channel for finding out about lots of Guitar related topics of interest, these are two videos that for most people adequately explain the differences and advantages of each.
And
I hope that these prove to be interesting to those of you who are curious!
Darrell
Good share and very interesting I think ? Watched the first video as I really know nothing about the internal workings of valve amps. Think I got about 10% max of what was covered but I love it when some gives 100% total HSE disclaimer, with a bottle of Laphroaig Single Malt sitting on his desk 
I’ll be back for part II. 
Yes it can be a bit difficult to understand unless you have some of the basics of electronics!
I always go by “valves can kill you, so don’t mess around with them” logic :D.
On a more serious note, thanks for sharing, need to watch them properly later but they both seem filled with useful info!
I only watched the second vid but that was pretty cool. I actually studied some of this stuff many years ago, long enough to pass the tests. I haven’t used much of that info in my work or personal life. I never got down to the periodic table in my studies but a lot of that diode and transistor talk reminded me of those days.
Before ever getting into playing guitar, I remember reading about audiophiles loving their tube amps vs transistor amps, claiming the sound was warmer and just more pleasing. I never had the financial bandwidth to hear this for myself but always wanted to see these purists subjected to the “pepsi challenge” to see if they could really detect the difference.
But when he said that the characteristic of the tubes isn’t better, its just what we’ve gotten used to doesn’t sit well with me. Music is subjective and “If it sounds good, it is good”, right?
I actually visited this section because I am considering a hybrid Micro Terror or Micro Dark from Orange. After seeing this, I am more convinced that tubes on the preamp side and transistors on the power side is the correct answer for home players like me.
Same here, and this is a contentious subject. But the conclusion I reached was that an awful lot of the high-end hifi world was snobbery, snake-oil and marketing feeding off each other.
I have no problem with people preferring the sound of valve hifi amps or vinyl records or, as I suspect, the wider experience of using such gear (the glow and smell of hot tubes, the ceremony involved in playing vinyl records, the large gatefold album covers). But, very often, the proponents of such systems (including the hifi vendors who are happy to sell snake-oil and to jump onto bandwagons) claim it is due to the technical superiority of such systems, when the realty is such systems have worse fidelity, higher distortion, etc.
My pet peeve in this respect are the unscientific claims that Red Book CD spec digital is, somehow, missing something that analogue-audio systems or high-resolution can bring back. Such claims are generally accompanied by the same level of rationality and quality of “evidence” that you would get from someone who claims our planet is flat.
The problem in the audio world is that hifi audiophiliia as a specific hobby grew up in a world where getting good audio quality was hard and expensive. That is no longer true: advances in technology mean that you can now buy a component that gives you, in every respect, audio reproduction that exceeds the ability of the human ear/brain to distinguish differences for a few dollars.
Even on the production side, it’s possible to purchase a DAW system (including AI, software, and PC) for a few thousand dollars which exceeds the fidelity specifications of the equipment in any analogue recording studio that ever existed (of course, there are many more factors to producing great sounding recordings than having good electronics).
That means a large part of what made collecting, tweaking, and obsessing over expensive hifi equipment has gone away. Improved quality at reduced cost should make a real “audiophile” rejoice, but it is often an anathema to them, which speaks volumes about their motivation.
However, whilst gear snobbery and snake oil is rife in the guitar world, I think there’s a big difference. Guitar players who prefer valve amps are specifically not interested in “fidelity” and are more interested in creative use of the valve technology and its inherent distortions to create interesting tones.
The way the amplifier circuits react can also influence the “feel” whilst you are playing (something that’s only apparent to the player) although this is very subtle.
I do agree that, to a large part, the sound of amps is subjective. There’s also some sayings: “we listen with our eyes” and, the alternative version: “we listen with our wallets”. To some people, the presence of “nice” gear impacts how it sounds to them. This is well known in psychology.
And a good part of the “valve amps are better” is, iMO, part of the marketing and mythology. In some circles there is almost a “thou shalt not question the superiority of valves” culture.
There is no specific characteristic of valve amps which make them sound or feel “better” than good quality solid-state/modelling amps. In my view, the preference is learned through exposure to them.
I would say most beginner/intermediate players wouldn’t have a strong preference either way in a well conducted blind test.
Firstly, there is no “correct” answer. There is only your preferred answer.
For home players, I would agree, if you are that wedded to wanting a valve amp. But, for most home players, I would say a solid-state/modelling amp is also a viable option. Personally I prefer my Katana over my tube amps most of the time.
But if you are predisposed towards valve amps:
The power section of most all-valve amps lends very little to the tone at lower volumes when it’s not being driven and, for almost all valve amps (including “low wattage” ones), driving the power section is very loud; too loud for most home use.
For larger amps, it can even be too loud for gigging use: a friend of mine used to have a 100W Marshall amp which sounded great, but all of the tone came from the pre-amp. In 7-8 years of gigging, he never was in a situation where he could turn the master volume up above about 3.
So, in those case, a solid-state power section is smaller, cheaper, less problematic and often sounds better at low volumes.
By the way, I have a Micro Terror and it’s a great little amp. The cabinet you can get with it is a little “boxy” but fine for low-volume use. It really opens up if you connect it to a larger cabinet.
I would go for the Micro Dark, as it has an effects loop, which can be useful.
Cheers,
Keith
I agree that the Audiophiles have got it wrong to a point, a tube amp does have nuances that are different to Solid state amps, if I remember correctly it has something to do with harmonics. From what I can recall tube amps produce even harmonics and Solid state odd harmonics.
I agree with the Orange micro dark if you want a hybrid amp, it’s a great little amp! What I will say is that the Orange Crush 35RT is one of the best amps I have tried, for what it is and what it costs it’s brilliant!
I am an audiophile and have built my own tube stereo amps. A bit different beast than a guitar amp. I am not afraid of high voltage!
That said, a good amp, stereo or guitar, is a good amp regardless of tube or SS. My favorite stereo is a well crafted SS amp. The differences are nuance and flavor.
Like a well made guitar, they may sound different, and you may prefer one or the other, but that doesn’t make anything wrong or bad.
If we are talking about guitar amps then, yes, the harmonic structure of (analogue) solid state and tube amps tends to be different.
The harmonics are caused mostly by overdrive/distortion. If you operate these amps in their linear ranges, you can get very low levels of harmonic distortion. But that’s the difference between hifi amps and guitar amps: with guitar amps you are deliberately driving the amp outside it’s linear range to create compression and distortion components for artistic effect.
For hifi amps, you generally aren’t doing that. A good solid state analogue hifi amp will produce negligible distortion when operated within it’s linear range. A valve hifi amp will produce greater distortion (and thus those “warm” harmonics") but this distortion is normally at a much lower level than a guitar amp.
I should point out that another major difference between guitar amps and hifi amps are the speakers and cabinets: with hifi they are, mostly, designed to sound “transparent” and to not colour the sound in any way. With guitar speakers/cabinet, they are designed specifically to colour the sound. The speaker/cabinet colouration is often a very important part of an amp’s tone.
With digital modelling systems, you can produce whatever harmonic distortion you want. Very often the power amp stages of digital modelling systems are “transparent” like hifi systems, and all of the amp tone is done through creating the harmonic distortion using digital signal processing.
This isn’t always the case. The Katana amps have an analogue class A/B amp output which will introduce some specific harmonic distortion, and the Katana speaker/cab is also more like a traditional guitar amp. Having said that, unlike many digital modelling amps, the Katana isn’t trying to emulate other amplifiers; it’s aim is to have it’s own tonal characteristics. In that respect, the Katana is more like an analogue amp than a modelling one.
Cheers,
Keith
Exactly!
It’s the claims of superiority (usually based on the price tag) that annoy me. Differences, yes (particularly with different amp topologies).
I suspect it’s actually a small but relatively vociferous group that are making most of these claims.
Cheers,
Keith
Absolutely, the brotherhood 
I started off on the Guitar side with a 10W Watkins Westminster like the photos enclosed, it wasn’t easy to get any crunch at all, only if you turned it up rather a lot and even then it was minimal. At the time distortion was frowned upon, you just didn’t play that was (remember the Marty Mcfly and the EVH thing!). It was a lovely simple little amp, volume, tone and tremolo!
My first decent stereo was again valve based, this tells all about it!
https://keith-snook.info/quad-ii-mods-grey-pair.html
I had an FM radio and a Pioneer turntable with it, it did sound rather nice at the time.
I’ve had numerous valve amps since, mostly used and of varying outputs from a 5W Fender Champ (my favourite) to a Fender Twin which I can’t remember the output of, but remember that it was a well and truly overkill . Now I have my Blackstar BEAM and a Hotone Mojo Diamond which are both S/S and they’re both great little amps.
My last Hifi setup was a Linn system which was fabulous, looking at the current prices I must have had money to burn .
Here is my Covid isolation set up this last November.
Guitars (Carvin, Larrivee), Katana, tablets and phone. In the background, my self built 300b tube amp, 8 W SE, below that my self made DAC (Buffalo iii attached to a cuties box, below that an old MacIntosh SS amp. The nice speaker are Acoustix Zen Audagio and the rough speaker is my own single driver horn (they rock).
At the condo in the mountains there is a Forte 55 and McCormick combo connected to some low end but nice enough Kef speakers. The synergy is my favorite with the British amp and speakers.
Maybe someday I will make a tube guitar amp, I have all the parts. But I don’t have a need or place to play that loud.
SImple differences
1: A class C solid state amp (a circuit which is not always on) doesn’t use much power
2: A class A solid state amp (a circuit which is always on) uses more power and keeps your room warm.
3: A Valve amp (a circuit which is always on) uses a lot more power - switch your heater off, you don’t need it any more 
Thanks Andy, I’ve learned something new. Will take note of the heat generated by my amp and try and guess if it is an A or C class model 
Do you really mean Class C?
Class C amps are generally not used in audio applications because they introduce large distortions. They are more common in RF applications.
I’m guessing you mean Class B?
Also, strictly speaking, amplifier classes can refer to Valve amps as well as solid state, as they use similar topologies.
It is quite common to refer to the valve-amp versions of Class A and Class B or AB as “single-ended” or “push-pull”
Cheers,
Keith
In essence, an amplifier’s class is based upon how much of the original signal is used through the circuit. More often than not, the percentage used is notated as an angular degree, or the angle of flow. Therefore, = 360 means that the full signal is used, and = 180 would be half of the signal. The angle of flow is also closely related to the efficiency of the amplifier. Let’s take a look at each individual class:
Class A
In this form of amplifier, 100% ( = 360) of the original signal is used throughout the whole circuit. The result is an upscale version of the original signal, unclipped and effectively amplified to a more intense, usable signal. These amplifiers are very energy inefficient however; because the amplifying element is biased to constantly be conductive, power is drawn from the source even when no signal is being input. In layman’s terms, the amplifier is drawing power even when you’re not playing. Up to one Watt is dissipated for every Watt used to amplify the signal. This 1:1 ratio means that as much energy is wasted as is used when managing the linear signal. To many players, this inefficiency is worth it; the main reason for a Class A’s linear signal function is the use of tubes. Tubes have asymmetrical output, resulting in even and odd-numbered harmonics. While this is chalked up to opinion, many players agree that tubes producing those forms of complex harmonics result in a higher-quality sound.
Class B
In these amplifiers, only half of the signal ( = 180) is used, resulting in a lot more clipping (distortion) but a more efficient system. The system only operated half the time, processing half of the signal, so it naturally uses less power. It is unusual, however, to find amplifiers using single Class B elements due to unusual output signal, and are more often found in personal radios and battery-operated devices than . Instead, they are quite often paired with with a matching push-pull element, resulting in a Class AB system.
Class AB
Relying on the use of two Class B units, a Class AB system is a pair of complementary push-pull devices, each amplifying ~55% ( = 198) of the original signal and combining them afterwards, resulting in a full signal. The reason why each device takes more than 50% of the signal is to ensure that the signals crossover and match up, and no device is completely shut off at any time. However, Class AB amplifiers are still extremely efficient. There is the risk of crossover distortion, where the mismatched signal ends clip once combined; at most performance volumes, the distortion is not easily noticed and a the power efficiency of the amplifier is considered to be worth it.
Class C
Class C amplifiers conduct less than 50% of the original signal. This results in an unusually high level of sound clipping and signal distortion. Class C amplifiers are extremely efficient, boasting up to about 90% efficiency. However, they are more complex than normal amplifiers and are not usually found in guitar amplification systems, but instead have vocal and other instrumental practicality. A Class C amplifier has both a tuned, or clamped mode of operation, and an untuned mode. When tuned, the amplifier is biased so that only one-half of the input voltage is utilized, resulting in less power dissipated and wasted after amplification. Again, in layman’s terms, only half of the signal is input, but it retains its form after processing. It is possible to bias the amplifier to end up producing a signal that is reactive to very specific harmonics, for instruments such as bells or tuned idiophones.
Class D
These amplifiers operate similarly to Class AB units, running two separate signals (~ = 198), but instead use switches at each transistor that can turn on and off when there is no signal input. The result is a moderately clean signal that is amplified using very little power. This class is usually only found in batter-powered mini-amps which rely on weak power sources and need as much life longevity as possible.
Class G and Class H
Guitar players will never play through these types of amplifiers!
Hopefully this clears up a little misunderstanding about amplifier quality and classes.
Generally speaking Valve/Tube amplifiers are Class A or Class AB.
Depending on your situation, buying an amplifier the choice can be very confusing.
Wow, @DarrellW ! I was about to link an article about amp classes, but you went and wrote one for us before I could even do that! Thanks!
I agree it is good for use to present accurate info so we are well informed!
Do you really mean Class C?
Class C amps are generally not used in audio applications because they introduce large distortions. They are more common in RF applications.
I’m guessing you mean Class B?
Also, strictly speaking, amplifier classes can refer to Valve amps as well as solid state, as they use similar topologies.
It is quite common to refer to the valve-amp versions of Class A and Class B or AB as “single-ended” or “push-pull”
Cheers,
Keith
That’s what the smilie was for! 
Going in to the various classes in detail wasn’t the intention - the whole post was a smilie!
…Although a Class C would make some some weird effects 
