HAD on tubes vs solid state

[phsyconoodler]

I beat you to 55.nov3
I just can't get any worthwhile live sounds from a solid state amp.But.....I can get a cool tone with my Heathkit 2-12 combo SS amp.Still not tubey though,but better than most all SS amps I've tried in the past few years.I work at a major music store so I've tried a few.

[martin manning]

With all due respect, I call BS on the crystal lattice comment regarding harmonics. I have done some studies in Solid State physics and can think of no reason why this could be true. If high order harmonics can't survive in the lattice then this implies a frequency limitation in the semiconductor...

I believe the idea is that since a solid-state device cuts off sharply and completely, any harmonics riding on the fundamental are eliminated from the flatted-off portion of the waveform, whereas the gentler onset of clipping in vacuum tubes allows the harmonics to persist as distortion is introduced.

[daydreamer]

I like the imagery of the vacuum making a difference. Whatever the maths is, so be it. Also, in space no one can hear you scream, so..yeah...

[vibratoking]

I believe the idea is that since a solid-state device cuts off sharply and completely, any harmonics riding on the fundamental are eliminated from the flatted-off portion of the waveform, whereas the gentler onset of clipping in vacuum tubes allows the harmonics to persist as distortion is introduced.

Yes that is the idea presented in the paper and it is logical. I believe that is a part of why tubes sound different. Any harmonics ALREADY present on the signal are affected differently as the signal approaches cutoff or saturation. This is not the whole story. Tubes also CREATE more even harmonics as the soft clipping of the waveform occurs. A different set of harmonics are created, mostly odd, when a SS device hard limits. This is part of the reason I posted the link to the Fourier applet. It shows you what happens to the spectrum for different signals. The applet is very insightful for those who are not familiar with how signals in the time domain correlate to the frequency domain. That may sound overly technical to some. For those that don't understand, the time domain is simply what a signal looks like on an oscilloscope. The Fourier transform is a mathematical method that 'transforms' the signal into its frequency representation. This is a fundamental link that must be understood to fully understand and design an audio/guitar amplifier.

I like the imagery of the vacuum making a difference. Whatever the maths is, so be it

I like the imagery of the vacuum tube too. Imagery and understanding are two very different things. Why wouldn't you be interested in having both? I would encourage you to spend a few minutes with that applet. The information is profound and a fundamental building block. Once you understand it, you will never look at an amplifier the same way.

[thyx]

SS vs tubes...the oldest guitar amp debate on the net. In fact, as has been pointed out, the debate existed long before we even had a net.

I think we need to focus on the word "survive". What does it mean for harmonics to survive?

SS certainly does produce higher frequencies...and therefor, theoretically, will produce all the higher-order harmonics that tubes do. And then some. Tubes roll off some of the higher order harmonics...which is a good thing. Try injecting a 27th-order harmonic into your tone and see what it does for it. The biggest difference is the dynamic way tubes handle your signal...especially when you're on the verge of overdrive. Your guitar really takes on a three-dimensional characteristic...which never happens with solid-state. That's because there's no middle ground with solid-state...you're either at a full-on hard clip, or you're not. And a full-on clip squares off the signal which produce all those nasty 27th and 33rd order harmonics that sound like fingernails across the chalkboard. The end result is that tube-amps, when set up right, can make your tone sound 3-dimensional...and almost alive. With solid-state, you're stuck in 2 dimensions...and there's nothing you can do about it. That tone Tom Shulz got with Boston sounds good...yes. But it still sounds 2 dimensional. I could tell this as a kid before I even started playing guitar. But none of this is anything new.

Now...regarding the survival of harmonics, what happens when you get higher order harmonics and mix them with phase-shifting at higher frequencies? You can get at least a partial cancellation of some of the lower order harmonics...which is what I believe those strange integers on the frequency analyzer are all about. While there's nothing new here either, I mention it because it's very seldom folks take phase issues into the equation. The only place where phase isn't an issue is in the laboratory.

So...back to the original question. Do harmonics survive in solid-state? I believe the answer is: sometimes they do not.

[mlp-mx6]

Tubes also CREATE more even harmonics as the soft clipping of the waveform occurs. A different set of harmonics are created, mostly odd, when a SS device hard limits.

Triodes create mostly even harmonics. I do not think the same is true for pentodes, and certainly not for push-pull output sections.

[Billion81]

which never happens with solid-state

Will this ever be fixed in solid state? That is to say- will there ever be a solution to get out of the 2 dimension sound from SS or is this a hard and constant limitation of Solid State?

[/i]

[daydreamer]

Imagery and understanding are two very different things

Without a doubt, I'll get there, just couldn't resist the low ball, it's all I got right now...

give me 6 months and I'll be throwing down some sine wave bending numbers like no-ones business!!.......now where did i put that beer?...

[vibratoking]

Try injecting a 27th-order harmonic into your tone and see what it does for it.

According to the Fourier modulation theorem nothing audible will happen. If I mix a 1kHz signal and a 27kHz signal, I will get sum and difference frequencies. This will result in a 26kHz and a 28kHz signal. Neither of which will be audible. Some power will be spent in the amplifier to generate these frequencies, but they will not be audible.

And a full-on clip squares off the signal which produce all those nasty 27th and 33rd order harmonics that sound like fingernails across the chalkboard.

I don't believe they are audible

The end result is that tube-amps, when set up right, can make your tone sound 3-dimensional...and almost alive. With solid-state, you're stuck in 2 dimensions...and there's nothing you can do about it.

I don't understand the 2 and 3 dimension comment. For me, the 3rd dimension of sound is something time based, like reverb, delay, chorus, etc... I agree a good tube amp has a more pleasing tone and feel than SS.

Now...regarding the survival of harmonics, what happens when you get higher order harmonics and mix them with phase-shifting at higher frequencies? You can get at least a partial cancellation of some of the lower order harmonics...which is what I believe those strange integers on the frequency analyzer are all about

What phase shifting are you speaking about? I agree there is cancellation happening, but why is it due to phase shift? How does that result in strange integers? Integers are integers, what is strange about them?

Do harmonics survive in solid-state? I believe the answer is: sometimes they do not.

And what is your reason for this?

I am not trying to be flippant. I am trying to understand your points.

[vibratoking]

give me 6 months and I'll be throwing down some sine wave bending numbers like no-ones business!!.......now where did i put that beer?...

Better yet, get out the beer and the Fourier applet - two for the price of one. You won't have to wait 6 months, maybe only as long as it takes to drink a 6 pack.

Triodes create mostly even harmonics. I do not think the same is true for pentodes, and certainly not for push-pull output sections.

Yes, I was not completely accurate. Triodes and pentodes do create harmonics differently. I was thinking in terms of preamp distortion, but you are thinking about the bigger picture. We are discussing the differences between tubes and SS. Tube output sections create odd harmonics the same as SS. In a Dtype circuit, harmonic content ,even and odd, is generated in the preamp and somewhat accurately reproduced by the output section.

[Structo]

Wow! The Fourier transform!

Haven't heard that term since my EE days at our community college.

I remember semiconductor theory being rather hard to fathom what with the hole theory and other things that were illogical.

I like tubes for their simplicity although I'm sure you can go very deep into them as well, such as Miller's Capacitance shows.

I've heard some great solid state amps (Hi Fi) so I know it can be done.
But for an amp that attaches to a musical instrument that we play with our hands, I still think tubes work better for that.

The touch sensitivity, dynamics and tone are all things that even the most elemental tube amp can bring to the table.

I really don't want the day to come when a SS amp sounds as good as a tube amp, because that will surely spell the doom of the vacuum tube at it's already weakened state.

T

[DonMoose]

I've heard some great solid state amps (Hi Fi) so I know it can be done. But for an amp that attaches to a musical instrument that we play with our hands, I still think tubes work better for that.

This is the critical thing - for REPRODUCING audio, solid-state is perfectly adequate. A guitar amp is part of the instrument - from input wiring to speaker and cabinet shape/size/construction. Tubes work better for that because they add the colors we want.

It's like the difference between a plastic clarinet and one made of real old-growth ebony. Or a FirstAct flattop and a prewar Martin.

[ER]

It seems like the dumble style amp would be more forgiving of a SS power section than many other amps. Clean, stiff Hi-fi output seems to be what he was going for. In fact I would say for a power amp on anything with a master volume this may be the least important link in the chain. Amplification factors tell you that the front end is more important, and since speakers are so lossy efficiency-wise due to the impedance mismatch with the air in the room, they're even more important than the output section.

I picked up an old peavey tube pre and SS power amp (T.B. Raxx and M2600) for $90 to use as a bass rig, but I already want to see what it will do as a guitar rig with the right preamp because it actually sounds pretty darn good with the soft clipping circuit it has. This is the first SS amp I've used after owning dozens of tube amps and it sounds good to my ears so far.

It really depends on the application, I've studied up on this a bunch and listened to many different amps both guitar and hifi and I'm still not totally convinced either way except for when it comes to phono reproduction and moderate gain guitar amps where tubes win hands down. Clean or high gain amps it becomes less important certainly less important than a good guitar and decent speaker cabinets. Efficient revealing speakers are the most important aspect of the food chain, you can hide a multitude of sins with colored inefficient speakers for both hifi and guitar.

It's a personal thing in the end it only matters what your ears like, who cares the reason...

I do think guitar will be the last thing still using tubes.

-E

[Structo]

I do think guitar will be the last thing still using tubes.

-E

That is why it is important that we get as many guitarists playing through tube amps as possible.

Just a guess but I think guitarists probably go through more tubes than the Hi Fi crowd does.
I think they are more likely to hoard tubes, but we tend use them up.
Once they find a set that sounds good it is likely to be left alone unless
they are pumping some serious watts out.

I know some guitarists that hoard or collect tubes but eventually the tubes are put to use.

If you have young guitarists under your wings, try to show them how good
tubes can sound and the feel you get when playing through one.
That will go a long way in preserving tube amps for music.
Also, try to mentor younger people in electronics and particularly tube
theory to create a legacy for the future generations.

[talbany]

I do think guitar will be the last thing still using tubes.

-E

That is why it is important that we get as many guitarists playing through tube amps as possible.

Just a guess but I think guitarists probably go through more tubes than the Hi Fi crowd does.
I think they are more likely to hoard tubes, but we tend use them up.
Once they find a set that sounds good it is likely to be left alone unless
they are pumping some serious watts out.

I know some guitarists that hoard or collect tubes but eventually the tubes are put to use.

If you have young guitarists under your wings, try to show them how good
tubes can sound and the feel you get when playing through one.
That will go a long way in preserving tube amps for music.
Also, try to mentor younger people in electronics and particularly tube
theory to create a legacy for the future generations. :D

+1

T