What makes a good tube amp a good tube amp and bad tube amp a bad one?

[billiejr]

Hey!

I'm new to "amp theory" and kind of wonder the main thing that makes a good tube amp a good tube amp and a bad tube amp a bad tube amp? Is it the quality of the electronical components, or how the layout is designed? mostly the speaker? or the tubes itself?
Probably a stupid question but anyway, i'm not sure.

Thanks

[potatofarmer]

None, because vests don't have sleeves!

What makes a bad album a bad album and a good album a good album?

Probably a better way of looking at it is "what makes (AMP X) sound like it does? Why does (AMP Y) sound different?" times infinity. There is no bad or good, only taste. And reliability I guess.

[ric]

As long as an amp is safe to use, even under reasonable to be expected failures, I'd say if someone likes it, for them it's a good amp.

Seems like anything changes everything. Ken Fisher is said to have manipulated layout for edge of stability to get the sound and performance he wanted. That calls into question if even a more stable layout is better. Maybe just different.

[billiejr]

Thanks for your answers So people building amps really just have to experiment with different parts and layouts to get the sound they want?

[ric]

Thanks for your answers So people building amps really just have to experiment with different parts and layouts to get the sound they want?

I started because I couldn't afford commercially made or boutique amps.


If someone wants some different type of sound or performance, there's modifying an existing amp, which devalues it, or build your own.

Then the never ending search begins!...

[teemuk]

So people building amps really just have to experiment with different parts and layouts to get the sound they want?

First and foremost I would put my money on experimenting with different kinds of circuits...

Parts...? Yes, they can -sometimes- introduce great tonal effects as well. But generally then we talk about parts like output transformers or loudspeakers. You know, parts that are objectively proven to introduce a great amount of distortions or frequency response changes on their own. Not basic parts like resistors, capacitors, inductors, semiconductors, vacuum state devices and such. Parts that have greater significance as being part of a circuit than being exceptionally unique on their own.

Layout...? That's usually the least effective method to achieve any discernible tonal effects. Layout is important but generally it effects more things like overall noise and hum level, stability, et cetera.

[eschertron]

... and then there's the argument that a good tube amp has the smallest negative impact on the US trade deficit.

[Chuck H]

Indeed. In light of our economy I will say that (if you live in the US) any tube amp you like that is made in the US is a good one to buy and all others are bad ones to buy.

[loudthud]

What really distinguishes the best guitar amps from the also ran is not the tone as much as the feel. It's usually called touch sensitivity or dynamics. It's is very hard to quantify or objectively measure, but you'll know it when to feel it. There is no publicly available formula for feel, the only thing you can do is copy some exsisting design and hope to capture some of the mojo.

[Tooboob]

Seems like there's lots of punting going on here. Yes, there isn't a good measure for the quality of the sound of a tube amp. It's quite subjective. But ...

We use arbitrary musical scales that have certain properties that make them sonorous, which our ears have learned to be comfortable with, and which we expect to hear. We share them in common within a culture, and we have attached emotions to various uses of them - minor is sad, painful. Major is happy, triumphant. Sevenths beg for resolution, etc..

Guitar amp tones are part of this arbitrary musical language. You really want a vintage Fender sound for old-school Jazz. Marshall is old-school rock. loudthud's dynamics are part of this too - they allow the musician to communicate better.

There are at least four of these amp idioms - Fender clean, Marshall distortion, "High Gain" (the latest one), and grunge.

I believe that you really can judge how well an amp addresses these idioms, allowing musical communication.

I watch some Zappa solos last night. You can appreciate the technique, but the man had his own idioms, and it really doesn't speak to the listener as well as more "traditional" guitar. It's kind of like reading poetry in a language you don't know.

Bobby McFerrin is an innovative musician, but he got his Grammy for "Don't Worry - Be Happy". With Extreme, it was "More than Words".

A guitarist should choose an amp that helps him express emotion, not one that is good at explaining the tax code.

[olddawg]

What really distinguishes the best guitar amps from the also ran is not the tone as much as the feel. It's usually called touch sensitivity or dynamics. It's is very hard to quantify or objectively measure, but you'll know it when to feel it. There is no publicly available formula for feel, the only thing you can do is copy some exsisting design and hope to capture some of the mojo.

But even touch is subjective. Sometimes I set in on someone else's rig. Usually it's a WTF moment. Same when someone sets in on mine. The old saying I believe is true. Although there are certain preferred amps for certain styles and situations by consensus, tone is in the hands!

[mac dillard]

Tough question to answer if you are looking for something that you can actually measure. I know that I have built a "good" amp when a player plugs into it and on the first cord/note/riff gets that look on their face. It is when the amp, guitar and player have really hooked up. If you have seen that look then you know what I am talking about. You see it a lot when you get a player that is use to solid state amps.

[Mick Bailey]

The difference is always the player. Jeff Beck playing through a Chinese Epiphone Valve Jr. would make you want to buy one.

[Justin Thomas]

On this forum, a good tube amp is one that works reliably and makes us want to play more. A bad amp is the opposite. We particularly excel at turning Bad Tube Amps into Good Tube Amps.

Justin

[olddawg]

The difference is always the player. Jeff Beck playing through a Chinese Epiphone Valve Jr. would make you want to buy one.

Hey.. I love VJs. Best $99 amp in existence. I gig with one (the head through an open back 12" cab) all of the time and have used them in studio.. The sound guys always say wtf is that?! It sounds great! Just don't expect much overhead, lol.