Why do we tube lovers love tubes?

[D.A.R.K.]

i think we like tubes because of how much they do color the sound,
and solid state for just the opposite. tubes have a much more extreme response and added harmonic content... they have compression characteristics when driven hard. i just did a tube shoot out with a friend to find the best tube for the pre in his neopak 3.5... we tried 5 different tubes, and every single one was different- extremely different.
so for me, i like tubes because of their extreme coloration.

 

[fdeck]

Interesting article, Corey. Read like a school paper, but had some interesting info.

BBE, wouldn't the boosting of odd order harmonics in SS amps also a form of distortion? If not, why not? Would these even order harmonics also be present in a SS amp that sounds tubey, such as the LMII? Or is it not possible?

There is some lore that different orders of harmonics have either pleasing or harsh tone. I won't go further than that on what sounds good or bad.

Rather than confuse myself about the orders of harmonics, I prefer to think about symmetrical and asymmetrical distortion. Anything that changes the shape of the input waveform is distortion.

Symmetrical: Some circuits distort the positive and negative portions of an input waveform equally. This includes op amp circuits, and most power amps used for bass, including tube, solid state, and the lightweights.

Some treat the positive and negative swings differently. This includes Class-A circuitry, both tube and solid state.

So much for the order of harmonics. Then there is "hard" and "soft" clipping. Hard clipping means that an overload signal reaches a limit, and hits a wall. Looking at the waveform in an oscilloscope, the tops and bottoms of the waveform look dead flat. Op amps and Class-AB power amps clip hard.

Soft clipping means that the tops and bottoms of waveforms end up being more rounded. Class-A circuits and interestingly enough, many Class-D power amps, clip soft. There is a good likelihood that soft clipping in moderation is pleasing if not inaudible. Lots of early recording media like magnetic tape exhibited soft clipping inherently.

Some early and badly designed circuits clip in pathological ways, like the entire waveform being inverted, and stuff like that. Good power amp designers try to avoid this like the plague. Some solid state effects pedals may incorporate these effects for really deep hard distortion.

Hard clipping produces more amplitude of harmonics at higher frequencies, which may account for them being more audible.

I hope that I have made it confusing enough. For better or worse, what is going on with harmonics is not strictly an issue of tube vs solid state.

 

[lobey]

It's the super clean sound for me.

 

[fdeck]

It's the super clean sound for me.

The thing that is puzzling about the "clean" sound of tubes is that it departs from an engineering definition of "clean." That's OK, it just means we need to be careful about our terminology,

 

[lobey]

It's the super clean sound for me.

If I can rephrase "clean" I will. My brain is fried right now from work.

EDIT:

As compared to the solid states I've played, tubes just seem to have more of a round, warm sound thats more filled out. I think that's more confusing actually.

 

[SoLongJake]

its possible for a tube amp to get very loud and stay clean, i would put forth Aguilar's db 728, its gets absolutely deafening and stays very clean. Teamed up with the DB 680 its blissful.

 

[Kindness]

The simple answer is distortion (including compression). To understand the answer takes a lot greater understanding of the subject matter than most care to develop.

 

[Baird6869]

I can only describe what I get from tubes over SS as "warmth". Not sure if I even understand what I mean.

 

[JimmyM]

There is some lore that different orders of harmonics have either pleasing or harsh tone. I won't go further than that on what sounds good or bad.

Rather than confuse myself about the orders of harmonics, I prefer to think about symmetrical and asymmetrical distortion. Anything that changes the shape of the input waveform is distortion.

Symmetrical: Some circuits distort the positive and negative portions of an input waveform equally. This includes op amp circuits, and most power amps used for bass, including tube, solid state, and the lightweights.

Some treat the positive and negative swings differently. This includes Class-A circuitry, both tube and solid state.

So much for the order of harmonics. Then there is "hard" and "soft" clipping. Hard clipping means that an overload signal reaches a limit, and hits a wall. Looking at the waveform in an oscilloscope, the tops and bottoms of the waveform look dead flat. Op amps and Class-AB power amps clip hard.

Soft clipping means that the tops and bottoms of waveforms end up being more rounded. Class-A circuits and interestingly enough, many Class-D power amps, clip soft. There is a good likelihood that soft clipping in moderation is pleasing if not inaudible. Lots of early recording media like magnetic tape exhibited soft clipping inherently.

Some early and badly designed circuits clip in pathological ways, like the entire waveform being inverted, and stuff like that. Good power amp designers try to avoid this like the plague. Some solid state effects pedals may incorporate these effects for really deep hard distortion.

Hard clipping produces more amplitude of harmonics at higher frequencies, which may account for them being more audible.

I hope that I have made it confusing enough. For better or worse, what is going on with harmonics is not strictly an issue of tube vs solid state.

So hard limiting, which we associate with harshness, can also be used to make the harmonics more audible and overall more pleasing to the ear if done in a tube amp? I'm trying to reach some sort of a conclusion over what you said, but I don't know if I'm getting it.

 

[JimmyM]

The simple answer is distortion (including compression). To understand the answer takes a lot greater understanding of the subject matter than most care to develop.

I'm trying to care, but I think it's probably out of the realm of an online forum. Still, we have some pretty in depth discussions on here, so it's not impossible.

 

[Kindness]

I'm trying to care, but I think it's probably out of the realm of an online forum. Still, we have some pretty in depth discussions on here, so it's not impossible.

There were no hidden digs in my comments, there are lots of topics people simply don't care enough about to get to the heart of the matter and that is not a bad thing at all - the world doesn't revolve around this matter (as much as you and I and others might love to talk about it in our spare minutes/hours on the computer). In this case, I think it is generally outside the scope of the forum, mainly because even amongst experts there are different theories. The simple fact is if you prefer your tone from an amplification system other than a pa style power amp, distortion is the reason why; the signal you are sending into the system is not the signal coming out. It may be compressed dynamics, it may be excited harmonics, it might be inherent EQ, it might be the sonic fingerprint of the transformer not the tubes , etc.

 

[Risen Ashes]

[Invalid or Expired Link Removed]

That was a great read! Very informative Thanks!

And Yes I love tubes!

 

[nysbob]

I just think the tube amps tend to sound more lively and musical. A SS amp will reproduce your bass at crushing volume with deadly accuracy...a tube amp just sings.

 

[jellymax]

maybe science can tell me why you like tube amps, but that article was like
reading greek or something.

i don't like a distortion tone for bass. rather i like tube amps at 1/2 to 3/4 power
giving a slightly compressed, bluesy, barky larky, punchy tone with a slight hint
of distortion. the natural compression seems to keep the highs & lows more evenly
audible no matter what note or dynamics you play. an excellent compressor could do this nearly as well but requires serious knob twiddling to get it just right.

 

[JimmyM]

I just think the tube amps tend to sound more lively and musical. A SS amp will reproduce your bass at crushing volume with deadly accuracy...a tube amp just sings.

Ya Bob, but I'm trying to narrow it down scientifically as to why we feel that way. And now along with that, I'm trying to also figure out why I get the same kind of SVT jollies from a 6 lb. Markbass amp that's all solid state. Easier said than done for a simpleton like me, I guess, but still worth pursuing.

 

[fdeck]

So hard limiting, which we associate with harshness, can also be used to make the harmonics more audible and overall more pleasing to the ear if done in a tube amp? I'm trying to reach some sort of a conclusion over what you said, but I don't know if I'm getting it.

My take is that the higher harmonics that we associate with harshness are the ones that are less pleasing. The more pleasing (to my ears when I listen to a well done distorted bass tone) are those which are noticeable when you hear the bass track by itself, but you have to make an effort to hear in the overall mix.

 

[black_labb]

there was a discussion reguarding why valve amps sound louder than tube amps in an amp builers forum. someone suggested that it was because of the output transformer. the output transformer may be part of the reason they sound so good to us.

really it has to do with non-linear operation somehow.

the amp will put something out that is not the same as what is going in. wether it is distortion (even or odd order harmonics, symetrical or asymetrical and at what level), some type of compression and response at different frequencies (and how distortion and compression work at the different frequencies).

i believe that the harmonic distortion tends to create a fuller sound by adding harmonics to the notes. ie, a 40hz signal would be distorting a bit (even at clean) creating some 80hz, 120hz, 160hz ... which fills out the sound to us, as the actual fundamental is barely sounding, and the lower mids tend to make it sound bigger.

remember, tube data sheets show that in normal operation (not at full output or anything) distortion is usually around 5-10%, depending on the tube and the circuit. solid state is usually around 0.1% or something like that. im sure that the distortion is at least part of the reason. i think the distortion level probably drops off quickly as the harmonics increase, which may be part of it as well

 

[metron]

I don't want to hear any nonsense about distortion. It has nothing to do with distorted tones. I prefer the sound of a tube amp running clean over an SS or hybrid running clean as well. And I don't really understand why. I know that TF's play into it, and I know that there's a certain tonality to it that I like. But I can't put my finger on it, and it seems to be discussed in vague terms like "pleasing tones," "mojo" and "vibe." Bill FM once posted that compression is why we like tubes, but didn't really expound.

So why do we like tubes?

Uhhh distortion? I play tube amps for what they give me that ss amps do not. They both provide clean amplification very well. Solid state is actually better for clean sound IMO. In fact didnt your amp comparisons show that it is not easy to discern ss from all tube with one sample recording of linear amplification?

I love the crunchy tone I get from tube amps. I have a V-4B for distortion use only. Frankly I dont understand why someone would lug around any tube amp for clean tone. Solid state does it just as well, weighs less, and can be much more powerful. When you get down to it at a gig, in a mix there isnt much difference between the clean tones from one circuit topology to another. Once that SVT starts roaring (distortion, compresion, whatever) thats the tone I want. Its that simple! Mojo and vibe are just synonyms for b.s.

 

[fretlessman71]

Ya Bob, but I'm trying to narrow it down scientifically as to why we feel that way.

You want to get scientific with a feel?

Honestly, I see where you're coming from, but do you see where I'M coming from, too?

I'm still learning about what I love about tube amps. When I fire up my Ampeg after the parts get here, I'll play for several weeks and let you know.

 

[joeydavidson]

I finally tried out a tube amp today, it was an Ampeg SVT II pro. It sounded impressive but it's hard to explain why, it had a 'full and deep' sound to it and that was with it at a fairly low volume.