[SonicTrance]

I see you have plenty of gear to keep you busy @UntilThen Happy listening!

 

[UntilThen]

I see you have plenty of gear to keep you busy @UntilThen Happy listening!

You bet Tomas. I wish you could come here and jam with me on head-fi gear. We will have so much in common and you can bring Infinity, Eternity and UntilThen here for me to audition. Yes there will be an amp call UntilThen and another call 'The End' hopefully.

Tomas, yesterday I heard an awesome system in my downtown head-fi shop. I stayed so long that I've to pay $12 parking fees.
Have a look at this post from me yesterday. Cannot double post so have a peep there when you have time and tell me what you thang?
https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/post-16109211

 

[BzzzzzT]

Hi everybody!

I’ve read this thread and have a question. It was said many times that these amps are not typical tube amps. Soundstage is not enlarged, treble is not smoothed, bass is more controlled, no tube rolling. It is closer to solid state amp.

So the question is: what is the point of tubes in Citadel? If somebody like SS amp sound, why not to buy SS amp? I assume there is something that Citadel does better than typical solid state. What is it?

This is a good question and it all boils down to harmonics. Our brains are very sensitive to harmonics. Tubes produce a 2nd order harmonic distortion that mimics how we hear real sounds. Solid state also produces some harmonics, but these are mostly 3rd order, and this does not naturally occur in nature.

So the question is how does this work. To give a direct answer, these added 2nd order harmonics make it easier for our brain to perceive the sound. This is because all sounds in our physical world produce harmonics, and this creates the timbre of a sound. Timbre is the qualities of a sound that distinguishes it from other sounds of the same pitch and volume. Say a cello or a violin playing the same note at the same pitch. The harmonics of both will be different and we will know that these are different instruments. Our ear has evolved to be extremely sensitive to harmonic as our hunter-gatherer ancestors needed to be able to distinguish certain sounds to survive.

Solid state does not mimic the natural world and creates mostly odd order harmonics, which are not found in the natural world. This creates a flatter stereo image. When we add harmonics it actually makes it easier for our brain to perceive and process the sound. In an audio amplifier this will translate to a more realistic and three dimensional sound. This also makes it easier to actually perceive detail because the added harmonics make the sound more recognizable to our brain.

Tomas's amps use a circuit that addresses the many unique requirements of using tubes. Solid state is used to drive the tubes and output transformers to their most optimal and linear condition. In the old days, this was not possible. This gives you less smearing of the sound and distortion, because the circuit is not sagging under load and is maintaining a consistent operation, when driving the tubes. You get the accurate sound of solid state with the harmonics that makes it easier for the brain to perceive sound; creating the 3d and more natural timbre that tubes are known for.

An analogy for harmonics is an atom composed of a nucleus surrounded by a whirling vortex of vibration called the electron cloud. The comparative solidarity of the nucleus is like the fundamental; the electron cloud is like the harmonics.

The first mode is called the fundamental frequency or first partial, or alternatively the first harmonic. The fundamental frequency is of vital importance because it determines the pitch of the note we hear. But in addition to the fundamental, there are other frequencies produced by other modes of vibration. These accompany the fundamental although they are not so distinct. The second mode, for example corresponding to halves, produces a frequency double that of the first. Consequently it is called the second partial. The 3rd produces a frequency three times that of the first harmonic; this being called the third partial, and so on. Theoretically, this extends into infinity, with each fractional part contributing it's own frequency to the mix of frequencies that we call tone. Timbre is complex and our ears have evolved to be very sensitive to harmonics. Tubes present sound in a way that makes it easier for our brain to physically process.

Sorry for the long winded explanation, but this is the reason why tubes sound different and whey people tend to favor them for listening to music and for various production purposes.

 

[SonicTrance]

This is a good question and it all boils down to harmonics. Our brains are very sensitive to harmonics. Tubes produce a 2nd order harmonic distortion that mimics how we hear real sounds. Solid state also produces some harmonics, but these are mostly 3rd order, and this does not naturally occur in nature.

So the question is how does this work. To give a direct answer, these added 2nd order harmonics make it easier for our brain to perceive the sound. This is because all sounds in our physical world produce harmonics, and this creates the timbre of a sound. Timbre is the qualities of a sound that distinguishes it from other sounds of the same pitch and volume. Say a cello or a violin playing the same note at the same pitch. The harmonics of both will be different and we will know that these are different instruments. Our ear has evolved to be extremely sensitive to harmonic as our hunter-gatherer ancestors needed to be able to distinguish certain sounds to survive.

Solid state does not mimic the natural world and creates mostly odd order harmonics, which are not found in the natural world. This creates a flatter stereo image. When we add harmonics it actually makes it easier for our brain to perceive and process the sound. In an audio amplifier this will translate to a more realistic and three dimensional sound. This also makes it easier to actually perceive detail because the added harmonics make the sound more recognizable to our brain.

Tomas's amps use a circuit that addresses the many unique requirements of using tubes. Solid state is used to drive the tubes and output transformers to their most optimal and linear condition. In the old days, this was not possible. This gives you less smearing of the sound and distortion, because the circuit is not sagging under load and is maintaining a consistent operation, when driving the tubes. You get the accurate sound of solid state with the harmonics that makes it easier for the brain to perceive sound; creating the 3d and more natural timbre that tubes are known for.

An analogy for harmonics is an atom composed of a nucleus surrounded by a whirling vortex of vibration called the electron cloud. The comparative solidarity of the nucleus is like the fundamental; the electron cloud is like the harmonics.

The first mode is called the fundamental frequency or first partial, or alternatively the first harmonic. The fundamental frequency is of vital importance because it determines the pitch of the note we hear. But in addition to the fundamental, there are other frequencies produced by other modes of vibration. These accompany the fundamental although they are not so distinct. The second mode, for example corresponding to halves, produces a frequency double that of the first. Consequently it is called the second partial. The 3rd produces a frequency three times that of the first harmonic; this being called the third partial, and so on. Theoretically, this extends into infinity, with each fractional part contributing it's own frequency to the mix of frequencies that we call tone. Timbre is complex and our ears have evolved to be very sensitive to harmonics. Tubes present sound in a way that makes it easier for our brain to physically process.

Sorry for the long winded explanation, but this is the reason why tubes sound different and whey people tend to favor them for listening to music and for various production purposes.

Thank you @BzzzzzT for coming here with your expertise! Very good post!

 

[baronbeehive]

Have a look at this post from me yesterday. Cannot double post so have a peep there when you have time and tell me what you thang?
https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/post-16109211

Looks like you are well qualified to judge the merits of SS vs tube amps from those trials you mentioned in that link.

 

[UntilThen]

Qualified I wouldn't say but I do know my likes and preference. Though TT2 + MScalar present a very detailed and high fidelity sound with Susvara, I find it lacking in texture and euphony. Once Auris Nirvana is added as amp to the mix, that's when I say, "ah, that's my kind of music". You could call it musical and I will call it musical plus still sounding very high fidelity. There's more body weight whereas prior to that, it was light and fleet footed.

Right next to me when I was auditioning the system, was a guy who does measurements of the equipment there. He told me Nirvana has quite a bit of distortion whereas the Chord stack is quite devoid of distortion. I guess he was referring to 2nd harmonic distortions. All these terms don't come to me naturally. This is not my profession. I only know what sonic tones I like and I find tubes musical where as pure solid state just clinical. I know this is purely preference. There's no doubt there will be one camp who will prefer just the Chord stack and equally there will be another camp who like me will prefer a tube amp in the mix.

 

[baronbeehive]

Yes some people don't realise that when they say they like a euphonic sound, say, what they are really liking is distortion. It's like saying that you like the sound of the Gibson Les Paul sound which has a sustained distorted sound which is characteristic. After all that is the sound of electric guitars, they would not sound the same driven by a clean sounding hifi amp.

BTW I've just checked out your posts on the HE1000SE thread.. and I think it's fair to say you like it a bit . (I'm assuming you still do lol). So I'm still looking forward to your impressions when you finally get to hear it with Oblivion.

 

[OctavianH]

Yes some people don't realise that when they say they like a euphonic sound, say, what they are really liking is distortion. It's like saying that you like the sound of the Gibson Les Paul sound which has a sustained distorted sound which is characteristic. After all that is the sound of electric guitars, they would not sound the same driven by a clean sounding hifi amp.

This is a very true statement which was also in my mind for some time. I guess Eternity will be my final test to understand how much I love distortion.

 

[UntilThen]

Yes some people don't realise that when they say they like a euphonic sound, say, what they are really liking is distortion. It's like saying that you like the sound of the Gibson Les Paul sound which has a sustained distorted sound which is characteristic. After all that is the sound of electric guitars, they would not sound the same driven by a clean sounding hifi amp.

BTW I've just checked out your posts on the HE1000SE thread.. and I think it's fair to say you like it a bit . (I'm assuming you still do lol). So I'm still looking forward to your impressions when you finally get to hear it with Oblivion.

It's a lovely kind of distortion. A natural kind of distortion. I call it harmony.

He1000se is on my head as I type. I'm going back and forth between He1000se, LCD-3f and LCD-X at the moment in my home. For comfort and best tone, I go for the He1000se. It's the best headphone I've heard and owned and loved by far. After hearing Susvara the other day at the shop for 2 hours with those outrageous price gear, I still think I can live with just He1000se but I do love the LCD-4.

He1000se and LCD-4 are the headphones that I love and I haven't heard them on my Oblivion and I would like for that to happen soon.

 

[BzzzzzT]

This is a very true statement which was also in my mind for some time. I guess Eternity will be my final test to understand how much I love distortion.

These amps are definitely not what I would call euphonic and some amount of distortion from tubes IS intentional as it creates some desirable characteristics. The distortion changes the perceptual characteristic of the sound but does not necessarily change it's character, if that makes sense. This circuit has less distortion than most tube amps. I find the amount it has to be ideal. Also the lower output impedance and nimble circuit gives better frequency response. Some examples of more euphonic amps would be OTL circuits and traditional SET amps. Traditional SET amps face a greater impedance with lower frequencies causing some pleasant smearing that gives a sense of warmth. The higher output impedance (resistance) causes more distortion and coloration in most popular SET and OTL tube headphone circuits. What I find to be the differences between this circuit and the others mentioned are a more nimble attack like solid state, greater bass articulation and a cleaner sound; this I attribute to the efficient circuit, less distortion and lower output impedance.

 

[UntilThen]

That's what I like about the Oblivion too. It's a great contrast to the other tube amps I have or had. Fast transient response, fast decays, there's still some tube tone. With the Infinity and Eternity, there will be even more. That's what Sonic says and he would know. However don't expect OTL amps kind of tube goodness.

Other aspects of Oblivion that I like are very wide soundstage, doesn't sound glaring like clinical solid states and not all solid states are tuned that way. Typical example would be v280 / v281 that is warm and exhibit tube tone.

 

[baronbeehive]

Also the lower output impedance and nimble circuit gives better frequency response. Some examples of more euphonic amps would be OTL circuits and traditional SET amps.

That's the clever part of these amps. Not having a transformer in OTL amps, or having anything between the output tubes and the output signal in OCL amps also for example, would appear to be ideal because nothing interferes with the audio signal, but then you have the problem of controlling the impedance, obviously the lower the better. By turning that idea on its head and putting in a transformer in the output stage in parafeed mode you can have the best of both worlds, good control over impedance and at the same time there is little to interfere with the signal. As Sonic has said even a modest output transformer in parafeed mode will do all that is necessary.

The balance has been perfectly struck between power requirements and control over impedance and parasitics.

 

[BzzzzzT]

That's the clever part of these amps. Not having a transformer in OTL amps, or having anything between the output tubes and the output signal in OCL amps also for example, would appear to be ideal because nothing interferes with the audio signal, but then you have the problem of controlling the impedance, obviously the lower the better. By turning that idea on its head and putting in a transformer in the output stage in parafeed mode you can have the best of both worlds, good control over impedance and at the same time there is little to interfere with the signal. As Sonic has said even a modest output transformer in parafeed mode will do all that is necessary.

The balance has been perfectly struck between power requirements and control over impedance and parasitics.

You definitely nailed it!

I just love tube amps and the different circuits. They all bring something different to the table. That's what I love about tubes. There are so many ways to go about things with different results. There is a lot of creativity! I love seeing what different builders come up with. I really feel lucky to own one of Tomas's amps. I have great respect for his electronic skill, knowledge, ear and creativity! I'm never going to part with my Citadel.

 

[UntilThen]

I love his beauty, I mean Oblivion. On the top of my rack, it's a head turner. Gosh I've not heard Oblivion in 3 weeks of isolation !

 

[OctavianH]

Guys, I never asked because it is not very important, but what weight has an UltraSonic amp?