Tube Amplifiers

[yogibear]

good point on the article !
Although again, most tube amps may not have anything of the above ie they are inside a box and there is no light and warmth seen Mine dont and you would know there is a tube only from the sound.

Some tubes just refuse to glow at all but there is still magic in the sound.

Music listening is all about emotions be it from tubes or SS. SS amps do bring out loads of emotions too.

However things get interesting when you just swap between an SS and a tube amp keeping everything else exactly same.

Been doing that lately with some fine SS amps vs tube builds…. Quite revelation it is.

 

[sachinchavan 15865]

While listening is about emotion, building the Amp/Speaker etc is all about science hence that does need measurement.

I actually do not agree with the original article on classifying tubes into emotion at all. it is the design of an amp which makes it analytical or bring the X factor on emotion.
Every recording has emotion since any decent musicians play with emotion..else there would not be any music. there are systems which reproduce it well , reproduce it badly and everything in between ! SS and tube should not even enter this discussion

Therefore Arjun, you’d notice, I didn’t use the words science/measurement, but only ‘closer to recorded sound’. Also, I didn’t mention Tube/SS.

But when people characterise tube sound, they usually use terms like ‘liquid/honeyed sound etc’ and attribute it to the even harmonics reproduction and say they sound sweeter than the odd harmonics. What I’d like to know, is does live sound consist of just even harmonics? If not, then why the need to make the sound sweeter than the original? And won’t then the reproduction of only even (or only odd) harmonics amount to distortion?

 

[Analogous]

Is it true that now a days it’s possible to design (and tune?) SS class AB and class D amplifiers to sound like classic Tube amplifiers and vice versa?

 

[Nitin K]

However things get interesting when you just swap between an SS and a tube amp keeping everything else exactly same.

Been doing that lately with some fine SS amps vs tube builds…. Quite revelation it is.

Can you pls let us know your views what you experienced on swapping to help solid state users understand . Thank you.

While listening is about emotion, building the Amp/Speaker etc is all about science hence that does need measurement.

I actually do not agree with the original article on classifying tubes into emotion at all. it is the design of an amp which makes it analytical or bring the X factor on emotion.
Every recording has emotion since any decent musicians play with emotion..else there would not be any music. there are systems which reproduce it well , reproduce it badly and everything in between ! SS and tube should not even enter this discussion

Very aptly said and totally agree with your view on this.

If you are really curious nitin, you can try adding a tube buffer somewhere in your chain and see if you like it

There are some well regarded ones from musical fidelity than apparently dont degrade the sound in general.

Thanks Mano, I am quite curious about tubes especially after hearing about the hybrid Vincent SV228. Currently using a solid state Marantz SR 7011 avr. Wanted a separate integrated amp for stereo to pair with the avr as a power amp in HT mode.
Unfortunately cannot hear them in Mumbai. It has tone controls and HT bypass too which ticks most of the features I need.

 

[arj]

What I’d like to know, is does live sound consist of just even harmonics? If not, then why the need to make the sound sweeter than the original? And won’t then the reproduction of only even (or only odd) harmonics amount to distortion?

Live sound has all harmonics and no system can ever sound like a live (unamplified) event. The best mastering/recording in a "best system" will still not sound as good as decent singer singing live for you

Even harmonics sound sweeter and some tubes do accentuate that but its not necessary that all tube amps do as in the end its also about the market that these manufacturers make the equipment for. If consider the amp only and take out the speaker just to make a point,

• Some people want Tubes and expect it to sound euphonic hence manufacturers make them like that
• Some people want hard hitting highly dynamic /highly damped sound hence amps are made like that
• Some dont care and want it to sound natural to their ears...
• etc etc.. so equipment manufacturers will need to consider which is the section of audiophiles they are targeting

Personally I do not mind a SS amplification but for low level signals especially in a Phono and to some extent in a Pre I would want a good tube design.

Is it true that now a days it’s possible to design (and tune?) SS class AB and class D amplifiers to sound like classic Tube amplifiers and vice versa?

i think it was always there and as in the above post yes its possible between SS and tube to some extent. I am not sure of Class D as its a long time since I have heard one but it never rocked my boat. maybe its possible today or in the future,.

Either way getting it to sound like a Tube should not what they should do...getting it to sound as natural as possible should always be their objective

 

[yogibear]

@Nitin K It’s hard to put in words. If you ever travel to Jaipur, you are welcome for a listening session. Yes, tubes win for me.

And as far as SS is concerned, I have a big surprise in store as well.

And try to experiment with a tube preamp in your chain and not a buffer.

 

[arj]

And try to experiment with a tube preamp in your chain and not a buffer.

+1 to what you say. Buffer is to solve a audio match problem not to "Tubify" sound !

 

[Nitin K]

@Nitin K It’s hard to put in words. If you ever travel to Jaipur, you are welcome for a listening session. Yes, tubes win for me.

And as far as SS is concerned, I have a big surprise in store as well.

And try to experiment with a tube preamp in your chain and not a buffer.

Thanks a lot Yogibear for your kind invitation. I will surely give you a heads-up much in advance in case if I happen to come to Jaipur. There is a lot for me to learn from you & your setups.

 

[yogibear]

Thanks a lot Yogibear for your kind invitation. I will surely give you a heads-up much in advance in case if I happen to come to Jaipur. There is a lot for me to learn from you & your setups.

Latest creation: 6SN7 Tube preamp. An eye opener for me. Probably simplest tube preamp with maximal tube sonics and wide frequency response. Excellent mate to both SS or Tube amps..

 

[coaltrain]

But when people characterise tube sound, they usually use terms like ‘liquid/honeyed sound etc’ and attribute it to the even harmonics reproduction and say they sound sweeter than the odd harmonics.

This is exactly what I used to think before I got into tubes. However, tubes amps don’t add harmonics at random; instead, it’s a by product of harmonic distortion. And ss amps do it too.

Below is an article I had found online many years ago, when I was researching tubes prior to my purchase. It’s a simple non-techie explanation of what’s going on and it made sense to my simple non-techie brain A bit lengthy but you might find it useful:

• Question:
  Why is there a difference in Tube and Transistor sound
• Answer:
  Engineers and musicians have long debated the question of tube sound versus transistor sound. Conventional methods of frequency response, distortion, and noise measurement have always assumed linear (clean) operation of the test amplifier and have shown that no significant difference exists. In actual operation most amplifiers are often severely overloaded with signal transients. Under this condition there is a major difference in the harmonic distortion of tube and transistor circuits.
  
  There are also significant differences in the construction of tube and transistor amplifiers that contribute to the sound. Tube amplifiers require output transformers to match the high impedance of the power tubes to the low impedance of the loudspeaker. The transformer has a natural high-frequency roll-off that makes the tube amplifier sound warmer. When the amplifier is overdriven the transformer also has a point of core saturation that provides a form of compression. This gives the tube amplifier sustain and a singing quality that sounds very musical. Transistor power amplifiers are either direct or capacitor coupled to the speaker load and do not have this natural compression. Negative feedback circuits used to reduce distortion in tube amplifiers are relatively simple. Negative feedback circuits used to reduce distortion in transistor amplifiers are more complex. The different types of negative feedback circuits in tube and transistor amplifiers react very differently to the harmonic content of the signal when the amplifier is overdriven. Tube amplifiers generally have a smoother, rounded waveform, where the overdrive of a transistor amplifier is more abrupt and resembles a square wave.
  
  The harmonic content of an overdriven tube amplifier consists primarily of 2nd order and 3rd order harmonics with some 4th order harmonics. The harmonic content of an overdriven transistor amplifier is primarily 3rd order with suppressed 2nd order harmonics. 2nd and 3rd order harmonics are the most important from a viewpoint of electronic distortion. Musically the 2nd harmonic is an octave above the fundamental and is almost inaudible, yet it adds body to the sound, making it fuller. The 3rd harmonic is a musical 12th. Instead of making the tone fuller, a strong 3rd harmonic makes the tone softer. The odd harmonics (3rd, 5th, etc.) produce a "stopped" or "covered" sound. The even harmonics (2nd, 4th, etc.) produce a "choral" or "singing" sound. Adding a 5th to a strong 3rd harmonic give the sound a metallic quality that gets annoying in character as the amplitude increases. A strong 2nd with a strong 3rd harmonic tends to open the "covered" effect. Adding the 4th and 5th harmonics to this gives an "open horn" character. The higher harmonics, above the 7th, give the tone "edge" or "bite."
  
  The basic cause of the difference in tube and transistor sound is the weighting of harmonic distortion in the amplifier’s overload region. Transistor amplifiers exhibit a strong component of 3rd harmonic distortion when driven into overload. This harmonic gives a "covered" sound with a restricted quality. A tube amplifier when overdriven generates a whole spectrum of harmonics. Particularly strong are 2nd, 3rd, 4th, and 5th overtones that give the sound a full-bodied "brassy" quality. Combining this reinforcing harmonic content with the compression and high-frequency roll-off of the output transformer in a tube amplifier is why your tube amplifier will "give it up" while your friend’s transistor amplifier will sound restricted and harsh

 

[coaltrain]

It’s a bar!!! Bottled nectar that intoxicates? The (visual) association is strong!

We are tuned to the same wavelength! Sine wave or brainwave, I’m not sure
Showed my wife the pic I took and she said they looked like tea light candles.
I looked at the pic and thought ‘Islay Malts!’

 

[Yelamanchili manohar]

+1 to what you say. Buffer is to solve a audio match problem not to "Tubify" sound !

There are some well regarded buffers out there, not the cheap chinese ones, which might be worth a try on the cheap

The MF X10D has positive reviews for taking off any digital edge or glare, some might call it tubey, but thats what it does.

A well designed tube preamp wont come cheap. So i suggested a buffer as a sampling process to decide if one wants to go the whole hog.

 

[arj]

There are some well regarded buffers out there, not the cheap chinese ones, which might be worth a try on the cheap

The MF X10D has positive reviews for taking off any digital edge or glare, some might call it tubey, but thats what it does.

A well designed tube preamp wont come cheap. So i suggested a buffer as a sampling process to decide if one wants to go the whole hog.

Actually a tube buffer is meant to ensure that a Source ( usually cdp) gets an easy impedance load from the amplification. It is actually a "impedance transformer"
Any benefit seen is when the CDP player is not able to drive the preamp. else it is just an another component in the chain and adding to the distortion....

I have used the X10D decades ago and would not suggest it unless your cdp cannot drive the amp

 

[Yelamanchili manohar]

Actually a tube buffer is meant to ensure that a Source ( usually cdp) gets an easy impedance load from the amplification. It is actually a "impedance transformer"
Any benefit seen is when the CDP player is not able to drive the preamp. else it is just an another component in the chain and adding to the distortion....

I have used the X10D decades ago and would not suggest it unless your cdp cannot drive the amp

Thanks for the explanation...well understood