You cannot generalize that tube has less power. Most Kt88 amplifiers have a lot more power than typical solid state amplifiers.
I don't think people also drive speakers at 110 db with the 100 watts available. So my wisdom is that this is not where the power is used. A low power, low feedback amplifier tube/ss will soften the dynamics. This is mostly the effect which is desirable for a lot of speakers which cannot handle the true dynamics of the records without sounding harsh.
Feedback has nothing to do with that, it is a way to linearize the low output power at the price of instability, phase shifts, and higher order harmonics sooner before clipping. The ideal amplifier would have lots of feedback techniques to cope with the inductance/reactance of the speaker loads.
I think what I need to buff this amp set I made is something like a QX2020 audio enhancement IC, or if my search turns up some thing better, that.
OMG a dsp audio empty start project ? No I don't think so. Looks like $100 for a cheap audio processor. If I can find where to buy the QX2020 I'd settle for it's simple no frills spice up for any plain stereo amp. Without enhancement of some sort, they seem to beam. That spatial expander is a big help.
I can play the same source through my receiver's processor and it leaves the bare amp sounding pretty thin.
OMG a dsp audio empty start project ? No I don't think so. Looks like $100 for a cheap audio processor. If I can find where to buy the QX2020 I'd settle for it's simple no frills spice up for any plain stereo amp. Without enhancement of some sort, they seem to beam. That spatial expander is a big help.
I can play the same source through my receiver's processor and it leaves the bare amp sounding pretty thin.
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Hifi is serious stuff, Scott Wurcer. 
OK, I must agree that the throttle/brake analogy wasn't good. It just fueled Satan, haha.
And I can't resist commenting on that cheap circuit's are prone to oscillate. Not at all, as soon as the circuit is designed and tested, it's fully stable and fairly easy to build as diy-er. All you need is to use a proper power supply and a good grounding.
We can discuss the pros and cons of NFB all the time, but many think low NFB amps simply sound better than a complex high NFB design such as the Honeybadger.
That one is a very good design but usually attract DIY-ers who simply don't know what to build and jumps on the "safest" train, since it has superior figures.
But i don't think that particular amp evokes passion among it's builders. The passionate people goes to the passlabs pages.
I think the reason for this eternal debate is that we tend to take THD as a bunch. Some people simply can't accept the idea that different distortion has different impact on our hearing. For example, second order harmonics are almost impossible to detect.
The guys from Meridian who put together the new MQA format presents facts that indicates that our ears are very sensitive to hf time related distortion. An amp with high NFB perhaps has some problem with small HF nuances - the feedback network simply is too slow. Until these thing have been proven or disproven we shouldn't take things for granted.
OK, I want to come up with an analogy. Maybe it makes sense or not.
A high NFB - "scientific" - design excels in removing the errors in the signal, producing a sound that's as least objectional as possible. An amplifier for people who simply want to sleep well at nights.
A typical audiophile type such as Nelsons minimalistic amps is better at making good things even better - the passionate approach. Perhaps a simple amplifier gives a simpler distortion pattern that doesn't confuse our hearing center as much, and that it's modest feedback path reacts faster on subtle changes.
Finally, Marcel I quote:
"Most of the amplifiers, the normal ones that are designed for non-audiophiles, have lots of negative feedback."
True, since audiophiles like a good sounding amplifier.
Regards folk's
OK, I must agree that the throttle/brake analogy wasn't good. It just fueled Satan, haha.
And I can't resist commenting on that cheap circuit's are prone to oscillate. Not at all, as soon as the circuit is designed and tested, it's fully stable and fairly easy to build as diy-er. All you need is to use a proper power supply and a good grounding.
We can discuss the pros and cons of NFB all the time, but many think low NFB amps simply sound better than a complex high NFB design such as the Honeybadger.
That one is a very good design but usually attract DIY-ers who simply don't know what to build and jumps on the "safest" train, since it has superior figures.
But i don't think that particular amp evokes passion among it's builders. The passionate people goes to the passlabs pages.
I think the reason for this eternal debate is that we tend to take THD as a bunch. Some people simply can't accept the idea that different distortion has different impact on our hearing. For example, second order harmonics are almost impossible to detect.
The guys from Meridian who put together the new MQA format presents facts that indicates that our ears are very sensitive to hf time related distortion. An amp with high NFB perhaps has some problem with small HF nuances - the feedback network simply is too slow. Until these thing have been proven or disproven we shouldn't take things for granted.
OK, I want to come up with an analogy. Maybe it makes sense or not.
A high NFB - "scientific" - design excels in removing the errors in the signal, producing a sound that's as least objectional as possible. An amplifier for people who simply want to sleep well at nights.
A typical audiophile type such as Nelsons minimalistic amps is better at making good things even better - the passionate approach. Perhaps a simple amplifier gives a simpler distortion pattern that doesn't confuse our hearing center as much, and that it's modest feedback path reacts faster on subtle changes.
Finally, Marcel I quote:
"Most of the amplifiers, the normal ones that are designed for non-audiophiles, have lots of negative feedback."
True, since audiophiles like a good sounding amplifier.
Regards folk's
Marcel : normal ones that are designed for non-audiophiles, have lots of neg feedback.
I say : its like placing a lot of bandages on a bleeding wound instead of curing the disease. In those amps we take the plague and hide it instead of fixing it.
In a good amplifier the feedback is just the polishing on an impeccable job
I say : its like placing a lot of bandages on a bleeding wound instead of curing the disease. In those amps we take the plague and hide it instead of fixing it.
In a good amplifier the feedback is just the polishing on an impeccable job
I actually kind of liked that analogy, gabdx.
But I must elaborate. I would say that even if the amplifier is impeccable before applying global NFB, a too large amount of it would destroy the outcome.
An amplifier is made up of several un-linear stages. The error signal that would be returned to the LTP will therefore have a quite complex harmonic pattern. That in turn will cause an even more complex distortion pattern at the output.
John Lindsay Hood, the old guy came once up with a nice analogy. It was something like:
"If we compare THD in an amplifier with a dent in a car, then NFB will have the same effect as if someone tried to hammer out the one big dent , causing a lot of smaller dents."
Sometimes it's less disturbing to leave the original dent.
I can't prove any of this but I think it's more useful to talk about the complexity of distortion than it's actual amplitude. Our brain is a fantastic pattern detector. If it confronts with a complex pattern ( possibly very weak in amplitude ) it just loses focus.
For example, 2:nd order harmonics is very easy for the brain to detect so it's not disturbed and can continue focusing on the music.
I think that's why simple designs are so popular among audiophiles.
But I must elaborate. I would say that even if the amplifier is impeccable before applying global NFB, a too large amount of it would destroy the outcome.
An amplifier is made up of several un-linear stages. The error signal that would be returned to the LTP will therefore have a quite complex harmonic pattern. That in turn will cause an even more complex distortion pattern at the output.
John Lindsay Hood, the old guy came once up with a nice analogy. It was something like:
"If we compare THD in an amplifier with a dent in a car, then NFB will have the same effect as if someone tried to hammer out the one big dent , causing a lot of smaller dents."
Sometimes it's less disturbing to leave the original dent.
I can't prove any of this but I think it's more useful to talk about the complexity of distortion than it's actual amplitude. Our brain is a fantastic pattern detector. If it confronts with a complex pattern ( possibly very weak in amplitude ) it just loses focus.
For example, 2:nd order harmonics is very easy for the brain to detect so it's not disturbed and can continue focusing on the music.
I think that's why simple designs are so popular among audiophiles.
What do you want to achieve with double blind tests? When the no-feedback amplifiers in the test distort so much or have such big frequency response aberrations that you can hear it, a double-blind test will simply confirm that there is a difference. People may even prefer the least accurate amplifier, just like electric guitar players usually prefer a slightly (or even grossly) distorted sound.
You could do subtractive tests. Out of curiosity I've done such a test on my high-feedback amplifier and found I still couldn't hear distortion when the music was attenuated by about 60 dB (and that was when I was about 25 years old and my ears were much better than they are now). Still, I wouldn't expect that to convince anyone of anything.
You could do subtractive tests. Out of curiosity I've done such a test on my high-feedback amplifier and found I still couldn't hear distortion when the music was attenuated by about 60 dB (and that was when I was about 25 years old and my ears were much better than they are now). Still, I wouldn't expect that to convince anyone of anything.
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Peter Baxandall and many other people (a few years ago, Bruno Putzeys) have shown the contrary.
This is true... when there is not enough feedback.
As Marcel suggested, you could do subtractive tests. It would certainly change your mind a bit. Here are some
Baxandall 1997 :
http://www.keith-snook.info/wireless-wor...ystery.pdf
Hafler 1986, page 6 and following suivantes :
http://www.hafler.com/pdf/archive/XL-280_amp_man.pdf
Renardson :
Simple Amplifier Testing.
Distortion Extraction
Distortion Measurement
Cordell 2010 :
http://www.cordellaudio.com/instrumentat...fier.shtml
Waslo 2008 :
http://www.aes.org/e-lib/browse.cfm?elib=14680
http://www.libinst.com/Detecting Differences (slides).pdf
There are only two types of distortion. NFB distortion and HIGH-END distortion.
No need for any more testing. Some people enjoy listening to audio with added harmonics.
We all apply Real-Time Error Prevention (or NFB as it used to be known as) when we are standing. How do we perceive this control? Is it gentle and precise with no errors taking place? Or, are you experiencing anything that would resemble throttle/break sensations with errors?
No need for any more testing. Some people enjoy listening to audio with added harmonics.
We all apply Real-Time Error Prevention (or NFB as it used to be known as) when we are standing. How do we perceive this control? Is it gentle and precise with no errors taking place? Or, are you experiencing anything that would resemble throttle/break sensations with errors?
I like these threads that has gone berserk.
But the only thing I have learned is that no one ever changes his opinion in this matter. For some reason this subject seems to provoke us. It's the fight between what our ears hear and what we think about it.
It's like when Dawkins tries to convince creationists that they are wrong. Totally impossible.
Wouldn't you agree that even if someone proved that no one can tell a NAD and a Krell apart, there would still be hi end stores out there.
**************Seriously************
I have one question to those of you that tend to be very pragmatic and who are convinced that a "blameless" amp ( complex, with NFB as high as possible yet with a proper phase margin) that is well made represents what is possible for humans to judge subjectively.
What are your personal experiences of listening to various amplifiers? Have you compared different types? Do you think your theories about NFB etc are confirmed subjectively?
Please, I'm not joking or trying to be sarcastic. Can't you let us know your practical experiences?
For me personally, I can tell that the "objective, Self-approved" amps simply leaves me cold. They have a sound that's mostly suited for military brassbands.
Lets have a poll!!!!!!
But the only thing I have learned is that no one ever changes his opinion in this matter. For some reason this subject seems to provoke us. It's the fight between what our ears hear and what we think about it.
It's like when Dawkins tries to convince creationists that they are wrong. Totally impossible.
Wouldn't you agree that even if someone proved that no one can tell a NAD and a Krell apart, there would still be hi end stores out there.
**************Seriously************
I have one question to those of you that tend to be very pragmatic and who are convinced that a "blameless" amp ( complex, with NFB as high as possible yet with a proper phase margin) that is well made represents what is possible for humans to judge subjectively.
What are your personal experiences of listening to various amplifiers? Have you compared different types? Do you think your theories about NFB etc are confirmed subjectively?
Please, I'm not joking or trying to be sarcastic. Can't you let us know your practical experiences?
For me personally, I can tell that the "objective, Self-approved" amps simply leaves me cold. They have a sound that's mostly suited for military brassbands.
Lets have a poll!!!!!!
Hifi is serious stuff, Scott Wurcer.
Maybe it would be better if we just settled this over some surströmming and beer.!
OK, guys. I'm gonna be a good example.
I have been thinking a bit since my last post.
I must hereby declare that I am a fool that has lost myself in the placebo minefield. A good super-blameless amplifier such as the Honeybadger has almost unmeasurable THD over the entire audio range.
Blind tests confirms that it's almost impossible to tell two good amplifiers apart.
So I will suggest that we all stop visiting DIYaudio since it's since long proven that a blameless amp is sufficient.
Good bye folk's, I will now leave diyaudio and lick my wounds. I will return when I can't resist the temptation to spread placebo teachings.
I have been thinking a bit since my last post.
I must hereby declare that I am a fool that has lost myself in the placebo minefield. A good super-blameless amplifier such as the Honeybadger has almost unmeasurable THD over the entire audio range.
Blind tests confirms that it's almost impossible to tell two good amplifiers apart.
So I will suggest that we all stop visiting DIYaudio since it's since long proven that a blameless amp is sufficient.
Good bye folk's, I will now leave diyaudio and lick my wounds. I will return when I can't resist the temptation to spread placebo teachings.
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