Why do audiophiles shun feedback in amplifiers?


I've owned several very highly regarded tube amps. Some of them allowed adjustment of the amount of negative feedback. I've always found some degree of feedback improved the sound...more realistic with tighter bass, dynamics, better defined imaging, etc. I have found amps with less or no feedback sound loose and diffuse with less dynamics... I know you should design am amp with excellent open loop gain before applying feedback. I can see the use of no negative feedback for low level amplification (eg, preamp and gain stage of CDP or DAC). So why this myth perpetuated by audiophiles and even many manufacturers?
dracule1
Hi Dracule1,
I `ve never read or been told that NFB exists within a tube`s internal/intrinsic construction.I don`t believe that"every amplifier" has NFB. I`m not an engineer nor a designer of audio components but I think some of them would disagree with your friends statement.When people talk of NFB it`s in terms of deliberate insertion into a circuit either globally or local loops.

But really it`s just what sound we all prefer.You like some NFB in your amps circuit and that`s fine.What ever no or zero NFB is, that`s what sounds best to me when properly implemented.This has been an interesting thread and I appreciate the various points of view.
Rgards,
NFB....love it or hate it.

Most things occur in shades of grey, not pure black and white.
Hi Kijanki - thanks for the link. I am going to have to ask one of my viola colleagues about this tomorrow! As far as I knew, the string lengths of all the instruments in the orchestra string family were approximately the same length (with the obvious exceptions of harp and piano), but that article claims this is not necessarily true of the viola. I am now wondering if this is a typically sloppy Wikipedia reference to viols, used in early music groups, which are of many different sizes, or if it does indeed apply to orchestral violas, which I tend to doubt. I will report back.

@Dracule - yes, audiophiles use quite a few terms somewhat differently than musicians do. My personal pet peeve is "neutral," LOL! But there are others, even such seemingly self-explanatory words as "mid-range." This is a very misleading term to a musician unfamiliar with how audiophiles use it, as it turns out that the vast majority of frequencies produced by acoustic instruments fall well within what most audiophiles call the midrange, though audiophiles will often disagree on exactly what constitutes the midrange. Other obvious candidates are "pace" and "timing." I have seen some very bizarre discussion of those two terms in particular on audiophile boards.
Learsfool, "neutral", in almost all cases, is a subjective audiophile term. IMO, only people truly qualified to use this term are recording engineers who have the capability to compare their recordings with the live performance that was recorded in their studios or venue. Don't get me wrong, as I've sinned too using this term in the subjective sense for lack of a better word.

As for "midrange", this can cover 200-300 Hz to 1-3 kHz depending on the audiophile. And yes as you state, this covers most of the frequency range of most instruments. That's why most audiophiles often proclaim the midrange is the most important because most of the music occurs in this range. Broad yes, but sometimes useful.
Learsfool, when you are not talking about orchestra musicians, the idea of long scale and short scale basses is well-known. A short-scale bass (electric, BTW) will have a neck about the same length as a guitar. A long-scale bass will have a longer neck, so the translation between the scale for a string bass player to a long-scale bass is about the same.

Long scale and short scale concepts are not used with classical instruments. But there *are* different sizes, at least with basses; I played a half-sized bass in jr. high, but my personal bass was a 3/4 size. As I understand it, full-size basses are rather rare- I don't think I have ever seen one. Most of the basses you see in orchestras are 3/4 size.
Hi Atmasphere - yes, I am of course familiar with 3/4 and 1/2 size instruments in the string world, I had just never heard the term "scale" applied to them, being purely a classical orchestral horn player. I would also like to take this opportunity to thank you again for all your highly informative posts I have read on this board over the last several years. You have a way of putting very technical subjects into layman's terms that is unequaled in my experience.
****But we audiophiles (and closet musician on the side such as myself)
have our own set of terminology that will befuddle most musicians. We use
many different terms to describe the similar, if not the same, thing (eg,
instrument tone, tonality, timbre, overtones, harmonics). ****- Dracule1

Yes, and that is a very real problem. It does befuddle that there should be
so little effort to understand and describe music in the same way (at least
as far as terminology, if not depth) that musicians do. At the end of the
day, this is one of the reasons that the sound of so many audio systems
bears little resemblance to the sound of live music.
Are you suggesting that there is a correlation between the descriptive definitions of musicians and various gear designers and consequently their result? Or just the systems that musicians put together vs. the rest of us?
Not exactly; but more the latter than the former. In the broad sense, what I meant is that I believe that if audiophiles would take it upon themselves to learn more about music at a level of understanding approaching the level of understanding that many reserve for the technical aspects of the playback equipment, their scope would be broadened in a way that would allow them to assemble audio systems that more closely approach the sound of live music; not to mention, enjoy music even more. Unless we dismiss the importance of what we may each learn about equipment via reviews, discussion forums, etc., the importance of using terminology that is universally used is obvious. As far as the more specific sense goes, let's look at some terms that are used frequently used in audiophile descriptive language that are problematic. A couple that come immediately to mind:

"Dynamic"- Often used to mean the ability to play loudly. It has nothing to do with loudness, but rather the way that the sound gets from point A to point B on the volume scale. Is it done seamlessly?

"Accuracy"- It is bad enough that the importance of comparison to live is routinely dismissed. The term is often used as a description without comparison to anything else; simply to connote a quality that is considered to be lean, bright, or lacking warmth (even natural warmth); playback that is "accurate" is anything but.

"Brightness/harshness"- Often confused. Harshness does not have to be bright. It is very possible to have a harsh sound that is too dark; just as it possible to have a bright sound that is round and smooth. Tonality is often confused with texture.

Musical, warm...the list goes on

   
But at the end of the day, do we not settle for what pleases our ears? It's a given that language itself is the largest barrier to communication. So even if we were cavemen running around with clubs, grunting our needs, we would still end up with what we want. Miscommunication just makes things take longer. Our individual perceptions of terminology used here may have us completely misrepresenting our gear but not necessarily preventing us from arriving at the same destination.
Frogman,
Your comment concerning "accuracy" rings true. Last night a friend and I attended one of our favorite jazz clubs.The quartet consisted of B3 Hammond organ,alto saxaphone,guitar and drums.The sound in this venue just sweeps you away with beauty and presence. Driving home we both kept referring to how rich, warm and full these instruments sound and project when heard live and up close.

What we both heard was the real deal,beautiful rich tone,complete fullness, weight and tonal saturation...accurate(because it`s real).
Components that strip away the'natural'charcter and result in leaner,thin tone(less color saturation) and body are`nt accurate,they`re inaccurate.I don`t understand why this approach has now become accepted by some as "accuracy". It moves further away from what you hear in the presence of live musicians doing their thing.
Regards,
Charles and Frog, I like your posts.

Going up one level on the "Structural Differential" :D

When products are measured with a bleached input, then the closer the bleached output is the more "accurate" that product is. Hooray for some, not so much for me.

I think this bleaching effect of reproduced music is at least one reason why I like SET's and especially 300b's. They add some of the "correct" color back to that live moment with their, OMG, 2nd order distortion.

Not to say all distortion is good. Give me a photograph of some green grass that the camera has bleached. Now if I put on some green tinted glasses, it's going to distort the photograph but the grass looks better to me. But put on some rose colored glasses and now the grass has a brownish tint to it. I still recognize it as grass but it's not as enjoyable.

I really don't want an accurate reproduction of a bleached event. I hear many boast of their .005% distortion amps. Maybe they enjoy brownish grass. To each their own, just don't tell me what to enjoy.
Onemug,
Yes, the objective (at least for me)is to capture as much of the true sound of live instruments that`s reasonably possible.That`s the best template I know of. I realize others disagree but I`ve found no better way to obtain good sound at home.
Regards,
Charles, in what sense is your goal a template? How and why would anyone disagree? What has the contention been so far in this thread? I seriously don't mean to be provocative but something's gone over my head here and "I don't know what it is".
Csontos,
I`m speaking in a general sense (not just comments on this thread). There are people who don`t believe that live music is useful or beneficial for judging the merits of audio components. Some advocate truefulness to the recording source as a more accurate approach.I don`t find that method the better option. Go through the archives and you`ll find more than a few of these advocates.
Regards,
Oh. I guess the entire chain of events is dependent on each link to arrive at the desired destination. I never looked at it that way. Makes a lot of sense considering the limitations of each component. But then you are limited by the recording source, aren't you? The best you can hope for is a general level of synergy. Then again, isn't that everyone's goal regardless of their point of view? Is yours a "method" or simply a different mindset? No matter one's approach, it seems in the end, we all find the light at the end of the tunnel. What's good is good, no matter how we formulate it. I can understand the stumbling block in relying solely on reviews when assembling a system. However your ears don't lie. Having to settle once money is spent is obviously the worst that can happen. Sad if we only find the light at the end of the tunnel when we can afford to. I've recognized a few heroes on this site so far. Not enough going on to single them out vs. the bs. though.
Csontos,
I imagine we all pretty much have the same goal but different approaches can lead one in different directions down the path toward that goal. I just keep it simple,hear live music and figure out the way to come close to replicating it in your home system.Everyone has their own way, that`s mine.
Regards,