The best that sounded on my breadboards was a hybrid amp, with augmented source followers loaded on counter-modulated current sources. It was a winter-only amp, though... Kind of sounding heater... 😉
The difference is, how well it fools imagination. If you hear a nice reproduction it is Hi-fi. If you hear as if real singers, musicians, waterfall, ocean, etc... in front of you, it is high-end.
like most people i like the sweet sound of tubes , but shouldn´t the best amp be the one that adds less distortion and coloration to the signal ?
i have 2 amps connected to the same tube preamp and cd player , in the arcam delta 290 the sound is " warm " higs seem rolled off , the cambridge audio 740 the sound is " colder " tighter bass , " open " highs , these are obvious colorations from both amps.
i have 2 amps connected to the same tube preamp and cd player , in the arcam delta 290 the sound is " warm " higs seem rolled off , the cambridge audio 740 the sound is " colder " tighter bass , " open " highs , these are obvious colorations from both amps.
Depends on what you are using the amplifier for.
If its for music reproduction then minimal distortion is paramount.
On the other hand of your a rock guitarist then coloration is everything.
Thats why most guitar music shops stil lstock valve amps.
The classis is a Marshall valve amp, loved by millions.
i play bass guitar 🙂 , those older marshalls like jcm800 are great amps for guitar , a guitarrist i played 14 years ago had one with his gibson les paul it was so good for hard rock.
But i was thinking about music reproduction hifi.
But i was thinking about music reproduction hifi.
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Sure. And tubes are the way to achieve that. Except, not "coloration to the signal", but coloration to the sound. It is controversial, and signal does not have colorations. It has alterations that can be perceived as sound coloration, but can be not. Like, better smoothness of transfer function adds less of sound coloration than better linearity of transfer function, if in order to achieve better linearity we sacrifice smootness.
WB,
Not to be critical, but how do you draw a distinction between 'smoothness' of transfer function, and linearity of transfer function?
I wrestle daily with these concepts, and I think I know what you mean, but I am uncertain. Are you referring to how quickly the curve changes direction?
Hugh
Not to be critical, but how do you draw a distinction between 'smoothness' of transfer function, and linearity of transfer function?
I wrestle daily with these concepts, and I think I know what you mean, but I am uncertain. Are you referring to how quickly the curve changes direction?
Hugh
on Vincent Hybrid amps for a while , maybe it´s time i try one !
Yes.
Nothing in the nature is linear, but everything that sounds good is smooth. All surfaces that generate sound, air that transfers it, reflecting and absorbing surfaces, everything is non-linear, but non-linearities are of low order. We filter out such distortions; no matter if Church or Darwin were right: we are as we are; and we don't hear distortions caused by physical media as distortions, even though they are alterations of signals.
Trying to get transfer functions more linear people often make it less smooth: like, adding 6 dB of negative feedback they reduce total distortions measured by conventional equipment a bit, but add higher order distortions that are more audible; we hear them well, they are alien to our perception.
About 0.001% of distortions: if such numbers are measured on almost full power, I can almost guarantee that the amp has significant phase intermodulation. And, if it is effective in terms of power consumption, it's distortions go up when sounds decay, and their spectrum goes wide. It is again adds very unpleasant distortions, that are inaudible when listening to clean sinusoidal tone, but awful in dynamics.
Phase intermodulation when equal to 10 microsecond delay (or greater) makes some details unrecognizable, like nails on piano keys, fingers on upright bass strings; our perception does not recognize them and renders like noise. They were clues for perception of the "real" soundstage, now they sound oddly.
Fire sounds like an ocean, ocean sounds like wind in savanna, everything sounds like some artificial noise, despite of very low THD measured by equipment.
The same happens with widening of spectrum of increased with decay distortions: they kill details, kill reverberation, audiophile say, "No air".
Such distortions of very good according to standard measurements amplifiers sound "dead". The "death" most often means presence of distortions that are similar to what I described above: distortions that can be revealed in dynamics.
Some people believe that "Dead" sound means "Ideal sound", and "audiophiles like especially distorted sounds". That is wrong. Audiophiles prefer sounds where "alien" distortions are absent, even if some more easily measurable distortions of low order, especially when they go up with higher power, and low down to the zero with lower power, are higher.
When transfer function is smooth, such distortions our perception filters out, and does not recognize as distortions. When we go for linearity, we in most cases loose smoothness adding nasty sounding by-products caused by measures we use to get linearity.
Because when you start with poor speakers, you try to compensate for their weaknesses.
you are right , in my opinion tube amps are more forgiving about speaker quality than other types of amp.
Hello
I presume that measuring phase intermodulation need more than a oscilloscope and a spectrum analysis with a sound card, how can we measure it ?
Can we see some of phase intermodulation in a Ltspice simulation ?
Thank
Bye
Gaetan
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Anatoliy,
I think we agree emphatically. I would be interested to hear what PMA thinks, I suspect he too might have something to say.
Your notions brand you heretic, surely?
You may need 're-educating', comrade......
Hugh
I think we agree emphatically. I would be interested to hear what PMA thinks, I suspect he too might have something to say.
Your notions brand you heretic, surely?
You may need 're-educating', comrade......
Hugh
alien distortions ???
That's a unique description. Or "non-musical distortions" ? I've been playing with a lot of fine voltage stages ... they are in the same "ballpark", clear , undistorted , reliable. I just completed a new OP stage and this improvement was more noticeable than just "swapping" voltage stages. How the amp interacts with the speaker seems to be a major factor. With tubes you are listening to the trafo , I heard a small Jensen trafo in the audio chain with the mighty genesis stealth (between the VAS and class A OPS). I've built the OPS of that amp but could not match that particular sound. Voltage stage loading is quite audible , whether you do it with resistors or EF2's. With the stealth, they loaded the VAS with a transformer ... making for that unique sonic character.
phase intermodulation = H3/5 ... PHASE INTERMODULATION.
I suppose these "bad" distortions qualify as "alien" (don't want any of them in my listening room 😀 ). Gm variation with both amplitude and load , very common with many projects here at DIYA (including some of mine). We can work around this with a few extra devices. CFP input pairs and a triple OPS would be a good start.
I suppose I am "double damned" ... as I believe in PIM as well as the need to "fix it" 🙄
OS
That's a unique description. Or "non-musical distortions" ? I've been playing with a lot of fine voltage stages ... they are in the same "ballpark", clear , undistorted , reliable. I just completed a new OP stage and this improvement was more noticeable than just "swapping" voltage stages. How the amp interacts with the speaker seems to be a major factor. With tubes you are listening to the trafo , I heard a small Jensen trafo in the audio chain with the mighty genesis stealth (between the VAS and class A OPS). I've built the OPS of that amp but could not match that particular sound. Voltage stage loading is quite audible , whether you do it with resistors or EF2's. With the stealth, they loaded the VAS with a transformer ... making for that unique sonic character.
phase intermodulation = H3/5 ... PHASE INTERMODULATION.
I suppose these "bad" distortions qualify as "alien" (don't want any of them in my listening room 😀 ). Gm variation with both amplitude and load , very common with many projects here at DIYA (including some of mine). We can work around this with a few extra devices. CFP input pairs and a triple OPS would be a good start.
I suppose I am "double damned" ... as I believe in PIM as well as the need to "fix it" 🙄
OS
Well they tend to soak the sound in 2nd order harmonics. By taking clarity away, you hear less of the speaker flaws. I wouldn't call it forgiving, just "compensating".
A good speaker always sounds best with (low crossover distortion) solid state amps with linear response and low output impedance... IMO.
You are right; some audiophiles sing anathema because I am an engineer, some engineers sing anathema because I dare to say that audiophiles indeed hear what they claim. 😀
Speaking of PIM, I remember JC promised to reveal some measurement method invented by his friend, from video measurements.
Even when its felt markers on a CD edge, or a magic potato ? No one here denies or accepts all the claims made by audiophiles, they need to be taken case by case.
Very depressing , knowing that different combinations and small design changes CAN have a audible effect on the soundstage. Some call you crazy and impress upon you that all amps sound the same. " If audible differences are heard , there must be a shortcoming or flaw in the design" was the statement that was a turning point for me , as I knew it was a lie. I'm sure this philosophy is why I was not accepted on the "other side".The heck with them. 😉
OS
Most instruments are rich in H2 , speaker distortion is H2 ... go with the flow.. 😀
OS
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