It looks like a debate to me.


I'm more interested in hearing the viewpoints of people that have earned stripes in the audio industry rather than faceless hobbyists.  Am I alone in this?

https://imgur.com/V0iwWex
128x128fuzztone
I didn't pay attention to who did it, I just saw bad assumptions everywhere. In the heat of defense I know I made a few.
You'r'e cool.  Stay well.
Groet.
oldhvymec I welcome your input any time.
However I recommend cannabis in lieu of alcohol for "getting along."
It works better for me. 

Well I happen to agree, we are on the same page there. As for the rest I was premature in my assumption it was SS vs Valve. I'm still not quite sure what the forum is for.  But here is the good news. I'm a good sport, let me read and learn. Sounds like politics in one form or another.

Respectfully and with regard
The only question posed was whether I'm alone in being more interested in a live debate about amp designs by amp designers. (NOT tubed vs ss since the panel members are not even determined yet.)The answer has been basically yes. I have no problem with that.
Agonners have commented that they prefer recorded over live as in their recorded responses and published studies. And some have stated that they trust forum members views over professionals, apparently due to some paranoia in believing that designers are charlatans and thieves. Except, of course, those designers that created their owned stuff.

Axpona 20 has been rescheduled if not cancelled.
I am NOT interested enough in it to forgo a planned weekend with grandkids.

I respect all opinions regarding facts.Not so much regarding fantasies, lies and vitriol.

oldhvymec I welcome your input any time.
However I recommend cannabis in lieu of alcohol for "getting along."
It works better for me.
Actually that was not the question. 

What is the question? ACTUALLY? Yea after another Agonner let me know my input was not what he asked for, I kindly replied "THEN ASK THE RIGHT QUESTION".  My answer had to ANSWER someones question....RIGHT? Even if it was about the planet Venus. Man oh man people are so picky....or PRICKY! is that a word?

Geeezzzz think I'll take up drinkin' might get along with folks easier HERE!!! Tough crowd...

Regards, maybe...
“Tube or not to tube, is that the question?”

Not one to niggle but shouldn’t that be tube or not tube? 😳
I'm more interested in hearing the viewpoints of people that have earned stripes in the audio industry rather than faceless hobbyists. Am I alone in this?

Tube or not to tube, is that the question?

Yes and no.. I like both, I like tubes in the mids (only) , I like SS bass and above 12k.  I like tubes from 100hz-12k. 

Faceless hobbyists
I'm more interested in hearing the viewpoints of people that have earned stripes in the audio industry rather than faceless hobbyists. Am I alone in this?  

YES YOU ARE.. YOUR the only one...

On these forums who else is here, and what constitutes STRIPES? If I'm reading this correctly, you want, "the PRICKS, and BITCHES, to keep their nasty, I drank to much, I don't feel good, mine is the best, my way or the highway, or I'm JUST AN ASSHAT to keep away from WHAT?  What is the question? or is it all the questions with the inference, "your a friggin moron for asking", or ignored all together.  Is it the response to the questions, or the statements? Refer to the above... Jealousy always brings unkind words.
The quality of the question you ask, can often determine the QUALITY of the answer you receive. 

I mean did someone offend you that much?.. EXPLAIN your position more clearly, and tell the naysayers, to fuc@off , eat shi?, and die.

Works for me... The dickhea#s your speaking of, have a contribution, just having to read between the lines is a pain in the hinderside... Yes means yes, no means no..

Now was there a question, or is this just a "blow off some steam" blog.

Did I miss something... AM I ONE??? Don't be shy... How may I be of assistance. For crying out loud.... IT'S ALL FREE. Then bitch about the service. LOL Don't be shy now, I'm NOT..oh yea!!!!!!!

Respectfully and hopefully with a since of humor.


@wolf_garcia , amen to your last post, and thank you for saying it. Enjoy the music.
One thing is for sure. It will not look like anything to me since the event has been rescheduled and I have a previous commitment.
Thanks to their wonderful 'no refund" policy I get to throw my tickets against the wall.
Where have you been all these years  ?   Nothing sounds the same  
Let's get that right.  
Oldguide...you can report all you want but keep in mind there's a tradition of free speech in some places, and to some a troll is anybody who doesn't agree with their particular point of view. Are you reporting anyone who seems passionate about something you disagree with? A self appointed judge of others is also a troll, and nobody needs to be looking over their shoulder to see if Oldguide the Church Lady is watching for tawdry posts.

desktopguy
I'm not a "hobbyist." My love of music (which propels all my audio systems appreciation), has way more amplitude than that snarky word can convey.
What is it about the word "hobbyist" that you think is snarky? There are many more hobbyists in this group - and I'm one of them - than there are professionals. There's nothing wrong with that.
This thread illustrates so well my love/hate relationship with this site, but also why I spend less and less time here. There are some people on this site who really know their stuff. I learn from them all the time. This thread has a bunch of those. But unfortunately it also has replies that are abusive to other members and ill-mannered. After enduring these for too long, I have decided to report abusive posts with the hope the moderator will put a stop to the abuse. I urge others to do the same, I have seen sites go South when the abuse gets out of hand and the trolls take over. The troll and abuse quotient of this site has multiplied considerably in the decade or so I have been a member. Judging by the replies of some to this thread, I am not alone in being frustrated by those who seem to have nothing better to do than hurl insults.

Post removed 
For the record:

  • I have a face (just checked...it's still there)

  • And I'm not a "hobbyist." My love of music (which propels all my audio systems appreciation), has way more amplitude than that snarky word can convey
I've earned my stripes by being a sought after and sometimes chased after (Get him! That concert was too damn loud!) live sound mixer/producer/destroyer. I've had my stripes ceremoniously ripped off in front of royalty also, along with banishment to an isolated island from which I escaped. Long story...however, I'm firmly in the single ended Tube camp which interestingly is a camp with a single end that sounds like music.
fuzztone - you sound like a sick puppy to me and I am not sure you can be fixed...
I stand by the intent of my original statement:

Amps seem to sound more sensitive to impedance issues to me than the math otherwise suggests.

@erik_squires I was not contesting this, FWIW.
There are far far too many other factors at play including open-loop bandwidth, compensation network, or just to make it simple, transfer function including load to simplify to an amount of feedback to equate to a particular sound.

Your simplification suggests a marginally unstable system as opposed to an over-damped system.
@heaudio123


Correct.


In order to present a nutshell explanation of how feedback is problematic (and also how to use it) the explanation has to be simplified and as much as possible use layman’s terms.


Open-loop bandwidth of course plays directly into gain bandwidth product, and compensation networks inside the feedback network itself and also in the actual signal path are of course important in any proper amplifier design. But the essence of my point is simply this:
If an amplifier has enough feedback, it won’t be bright and harsh, whether tube or solid state. Historically we’ve not seen really such an amplifier- that is why tubes are still around!


IMO most amplifier designers don’t really know how to design a proper feedback loop (as you know its far more than just a simple resistor). Meanwhile the test and measurement folks seem to realize there’s some dirt to sweep under the carpet which is why you rarely see THD analysis with the fundamental much more than 100Hz, with harmonics in the ear’s most sensitive region simply not displayed.
heaudio123
That's what I'm talkin' ' bout.
I'm more interested in designer input.
I don't care in the least that few members seemingly are that.
Level of interest and disrespecting other viewpoints are mutually exclusive in my book.
atmasphere, as someone who designs amps (for many applications), I cannot agree at all with your comment w.r.t. amount of feedback and sounds profile. There are far far too many other factors at play including open-loop bandwidth, compensation network, or just to make it simple, transfer function including load to simplify to an amount of feedback to equate to a particular sound.

Your simplification suggests a marginally unstable system as opposed to an over-damped system.
I stand by the intent of my original statement:

Amps seem to sound more sensitive to impedance issues to me than the math otherwise suggests.


Peace, @atmasphere

Best,

E
I find the louder the voice in the audio industry, the more likely the stripes are painted on.
To review, it is a seminar. All are invited.
It is ONLY billed as "John Atkinson, a panel of pedigreed amplifier designers debate what matters most when it comes to amplifier sound quality."
Expounding on what most of us already know about distortions and hearing does not change that. It might devolve into meaningless hype. It might not.
You'll never know if you're not there because any subsequent reports will be "distorted."
Ralph - yes of course, three positions all incorrect. And they all measure different. RM like you was about learning, the RM9 evolved to MK2, so on. I think some of your  amps are on MK3.3 ?

 My reference amp has single ended output, 5 parts in the signal path, no emitter resistors, no global feedback , liquid cooling, analog circuits for bias and pump control , mechanical truss isolation, ten regulated supplies... and alas is as all things made by man, imperfect.
Erik - of corse there is a lot more than time and phase... pistonic drivers, low diffraction, impulse, energy storage in the cone and cabinet, reflections from the magnet structure, the list is long ... like a series and patents since 1977
I will argue that we are also more susceptible to damping factor and speaker/cable impedance than we think we are, but I, in a very lage part, agree with Ralphs point, that the distortion profile is probably a large, large factor in likeability.
About that- amplifiers are far and away out in front of speakers in terms of development. One problem here is that no speaker needs more than about 20:1 for a damping ratio (not 'factor' mind you- 'ratio') and many solid state amps have far more than that, resulting in a coloration many audiophiles like called 'tight bass', something that does not seem to exist in the real world.
Roger M RM-9 has 3 feedback settings so you can dial into what your ear brian likes in a 3D world....
Not to put too fine a point on it but it can be seen as obvious that none of the settings would be correct. The RM-9 simply didn't have the gain or bandwidth to support enough feedback to really do the job properly. So any of the settings would have been a compromise.


We used to put similar amounts of feedback in our amps back 30-40 years ago, only to find that it did terrible things to the soundstage and tonality.


You can look at the deliterious effects of feedback on a Bell curve. A small amount of feedback does little damage but has little effect too- no more than about 2-3 dB. 12-20 dB is in the peak of the Danger Zone; so you will experience increasing brightness and harshness from about 4dB up to that point; above 20dB the harshness and brightness heads back to 'normal' but since very few amps have in excess of 35dB essentially 99 44/100s of all amps that run feedback will have a coloration of brightness and will be harsher than real life.

If you've ever wondered why two amps can measure flat on the bench but one is bright and the other isn't, this is why.


Hi @tomic601

I hate to be the spoil sport here, but I know I'm not that sensitive, and experts I trust also say this.

I believe some people are very sensitive to this issue, but I've never heard a time/phase accurate speaker wow me just because of that.

I point you to this article, which has three different experts on the subject:

https://audioxpress.com/article/zero-phase-in-studio-monitors

Like I said, I know I can't hear this, maybe others can, but I don't think those who can are the majority.

Best,

E
And the ear brain is highly sensitive to time and phase... no debate there either... ha
Roger M RM-9 has 3 feedback settings so you can dial into what your ear brian likes in a 3D world....


It should not be a debate. If you have a tube amp that ’measures poorly’ yet seems to sound just fine (as has often been seen in the pages of Stereophile) and an amplifier that measures just fine and is really ’neutral’ but not particularly musical then you have two amplifiers that sit at the opposite spectrum of the same problem, which is distortion and what to do about it.


I will argue that we are also more susceptible to damping factor and speaker/cable impedance than we think we are, but I, in a very lage part, agree with Ralphs point, that the distortion profile is probably a large, large factor in likeability.

In large part I think my own love/dislike for certain amps, and those fanboys on the opposite side of the room probably has to do with exactly what @atmasphere is talking about here.
@atmasphere has pretty well spelled it out; here’s the Cliffs’ Notes version, IMHO....

-The manufacturer makes a product; ’cherry picks’ the details.
-The vendor displays/demo’s same in the best way possible.
-The buyer ’places’ his/her bet on the item.
-The likelihood that the outcome is Great or Perfect is subject to items’ final location, application, and attached components.
-Buyer forms final Opinion of outcome.
-Buyer posts on AG to cheers/jeers.

That ought to cover it....
Fantastic post, Ralph (Atmasphere).  It should be a "stickie," if that were possible here.  And FWIW every word of it makes perfect sense as far as I am concerned.

Best regards,
-- Al

Since I was not invited (for good reasons as you will see) to the seminar I'll just make this post-


It should not be a debate. If you have a tube amp that 'measures poorly' yet seems to sound just fine (as has often been seen in the pages of Stereophile) and an amplifier that measures just fine and is really 'neutral' but not particularly musical then you have two amplifiers that sit at the opposite spectrum of the same problem, which is distortion and what to do about it.

In this regard with **all** amplifiers the sound of them is all about how they distort.


In this regard each has chosen a different path. On the one hand, a tube amp that 'measures poorly' is probably not running any feedback to suppress distortion, and one might want to know why not? The answer is that feedback adds distortion of its own, and what it adds is highly audible in the form of higher ordered harmonics (at low levels) and IMD. The human ear is keenly sensitive to both types! OTOH, the ear **isn't sensitive to the lower orders (2nd, 3rd and 4th), which is why that tube amp measured so poorly as it probably has much more of these in exchange for keeping the higher ordered stuff inaudible.

The solid state amp employs feedback as it has to to prevent it latching to the power supply rails (which would cause it to have a lot in common with a rock) and to allow it to be linear. So it inherently is much lower distortion, but now most of that distortion is of the form to which the ear is keenly sensitive, and comes off as brightness and harshness, since the ear converts all forms of distortion into tonality.

Again this should not be a debate! The common problem here is that neither amplifier has enough gain bandwidth product and so is a set of compromises. Tube amps, unless OTL (Output TransformerLess) usually have poor gain bandwidth product. Solid state amps usually do much better in this regard. But neither has enough- and this is what that looks like: without enough gain, you can't apply enough feedback so that the application of feedback allows the amp to correct not just for simple distortion but also the distortion caused by the application of feedback! Did you get that? Its sounds recursive because it is. Feedback can correct for itself if **enough** is applied. That value seems to be a minimum of about 35dB and 40dB is better.


But that means that the amp has to have a lot of gain so that once you blow 35dB or more away you still have enough to work with the preamp and speaker, so the open loop (no feedback) value should be at least 60dB!


Now we come to the other bit of that gain bandwidth product thing: bandwidth. Sure you can make a tube or solid state amp with that much gain, but when you run feedback around it there is an enormous possibility that it will oscillate. The reason is that when there is gain there is also phase shift caused by limited bandwidth- the more gain you add, the more the bandwidth is compromised. The phase shift can thus cause negative feedback to become positive feedback at some high frequency- and then it oscillates. A related idea in amplifier design is that of 'phase margin' which is to say that if by the application of feedback the amp oscillates, it has insufficient phase margin. OTOH phase shift causes the feedback to become positive rather than negative. 


So one way to deal with this is avoid feedback. You avoid brightness and harshness because the lower ordered harmonics mask the higher ordered harmonics. But the amp will measure poorly unless extreme steps are taken to suppress it by other means.


The other way is to stare down the gun barrels and add the feedback- now it 'measures' well but it has a brighter and harsher presentation than real life.

IOW **neither** amp is right! So this shouldn't be a debate. Instead we should be looking at the measurement standards- its obvious that since the ear is insensitive to lower ordered harmonics that they should not have the same value in the measurement as higher orders; IOW the various harmonics should be weighted. But in addition, the 2nd and 3rd in particular can mask the presence of the higher orders, so those harmonics should be in attendance in order to allow for something that sounds like music instead of electronics. But our current measurement regime takes little of that into account. In a nutshell, in this regard one of the most important aspects of human hearing (the fact that the ear senses higher ordered harmonics to gauge sound pressure) is ignored in order for the spec sheets to look 'nice'.


So this should not be a debate so much as a seminar on informing the public what is really going on. Sadly, it will probably just be a debate.
Kaitty's system: Grado SR60 or 80 utterly mediocre headphones with the foam ear cushions removed and a Sony Walkman CD player. Right Kaitty? There might be green sharpie on the edges of the  CDs which certainly elevates this system to true High End so yeah, he knows what's what.

Rather have feedback from Industry professionals vs hobbyists

Pros vs Joes, huh?

Why? Are all of them in agreement with each other now?

OP > If alienating people is not your forte, hang in there. It will be soon enough as you are definitely headed in the right direction by candidly dismissing our humble faceless & ofrten selfless pundants.

Or maybe This is just a tad shortsighted post whose intent is to infuse mor activity from manufacturers and or designers into the fray. Well, good luck with that.

Whenever a pastime revolves around personal opinion, be it faceless those of our hobbyists or a our designer's opinion, it is tainted by subjectivity and as such is a thing as malleable as human morality and as capricious as the winds

IOW, to which individual at the end of the day, will you subscribe simply on faith be it producer or end user?

If I want to get candid experiences, knowledge, or insights on something I know nothing about, or not very much, and Iíd not care to send off letter after letter to this makerís offices or that one, the quickest path then is to glean information from those who have actually fixed a transmission, built a house, recarpeted their living room, or here, put together a few or even many various audio arrangements in likely quite different rooms, locations,etc. and on various levels of investment.

Additionally, users, members, or just the run of the mill enthusiasts often do not have anything to gain from imparting their EXP via associated or various threads, as might those whose product sales are how they keep their refrigerators filled, their lights on at home, and their children fed.

OJT ëhands oníí first hand EXP or training used to be considered the most practical   form of education and in many arenas, still remains the best teacher.

Lets reviewÖ
makers, designers manufacturers and dealers all have a visible and valid motivation to further their professional interests, albeit many of that ilk on these pages do not share their technical eXP as self serving advisements, or tips.

But then really, whoís to say which is extolling the truth and who is embellishing or slandering facts?

Time, application and your own outcomes will validate other folks input/feedback on what ever topic you chase provided you pursue the path or paths others supply you their EXP.

OrÖ are you the sort which only follows those whose superficial credentials or social wcircles intimate they are elete, even if arguably so?

It costs nothing to ask things around here, and it costs less to receive the feedback this forum promotes. Within it are numerous highly skilled, experienced well intentioned individuals whose routine motivation is to help another.

as viable in any darkened web forum there will be that element of nay sayers and dissidents, so assimilate accordingly.

some members here are current or former technicians, designers, producers, dealers, engineers, etc., often found in the guise of mere members of an online audio oriented public forum.

Iíd not wish to alienate these from assisting me going forward as cases may be down the road.
given the price one pays for information embedded on these pages, this joint is a veritable gem!

enjoy!
Now this a lot more constructive than grade school name calling.  I endorse relevancy. Next time I'll post more facts to avoid confusion.
In through the nose out through the mouthand repeatMMM... Im feeling better already!
tooblue:

... SHARP-POINTED truth: I guess I'd agree that a comments' relevance to topic should be of paramount importance (and value to the 'conversation'/forum discussion)...
" could # of responses/forum comments be relevant? " only if they were relevant to begin with.
... Take all comments with a grain of salt and a grain of truth.

Verify with your own experience... be open to others statements (ask if by experience or by opinion and be 50% sure they are truthful in their response) and remember things that were heresy years ago SOMETIMES PROVE OUT...

Could # of responses/forum comments be relevant?
Most people have not (rpt not) heard a truly great system. I’m not going to speculate why that is. They might think they have, sure. That’s why the old wives tale of live music being the absolute sound persists. It’s like a virus. No live venues sound alike so how can live music be the ideal. Do you think a crappy venue still sounds better than a good home system? Give me a break? There is no absolute sound. Yes, I know what some of you are thinking, “But how do you know? Are you out of mind?”
Folks,
All sensory perceptions are filtered through our brain of biases and past experiences .  That is what subjective implies.  This hobby or passion of ours may have different motivations for different people, and those individual choices should all be fine and tolerated.  There is no absolute right or wrongs here, and to engage in "argumentum ad hominem" makes no sense....perhaps the late Harry Pearson was correct, in that the "Absolute Sound" is that of the live experience, which I believe can be approached but never equaled in the home listening room.  It is all a REPRODUCTION...whatever pleases each of us, and whatever each of us finds "better" or "worse" is fine with me.  Perhaps we should chose to say which items we prefer, not which are better....Is one great artist better or worse than another, or does one please us more?  I one delicious meal better or worse than another, or does it just please us more?  Similar themes, I think....PEACE
An encouragement, which I attempt to follow myself when offering what I feel is indisputable advice, knowing that a certain percentage of the Agon population will no doubt disagree, to add "YMMV" or the phrase, "IMO" or similar to the post. It is relatively easy to avoid needless offense when making a strong statement if a bit of respect for those with differing opinions is given.  :) 

I have been guilty a few times of making absolute, harsh, or critical statements without adding that caveat to buffer the criticism, and the result has been predictably negative, rancorous. I am trying to be consistent in that regard now. I encourage our people who hold strong opinions and feel that they have some special insight in regard to systems to show some consideration about how they provide the community their opinions. 

Now, in regard to the OP, I don't see anything terribly earth-shattering about the issue. Not surprising at all to me that SS/tube and perhaps what we could call variant specifications yield divergent opinions on performance. The spectrum of performance, the variety of systems, and the preferences of listners/reviwers is SO vast that I would be shocked if such things did not happen! 

I recall being at a reviewer event where a new product was on demo in various modes. I thought the whole thing rather insipid as to the performance change to the system between modes, and I suggested that the change in modes was no greater than I could achieve with a change of a power cord or two. The other reviewers were effusive in their praise for the sonic changes, so I was distinctly in the minority. I couldn't help but think the reaction was overdone in a bid to solicit a review.

While I wasn't impressed by the different modes, I thought the unit might be interesting to review for other reasons as to its design, as it is unknown in a solo demo how it might compare to other products. But, the experience reinforced the fact that there is a WIDE spectrum of experience with components and there will be no universality to perception of their performance, even among reviewers regardless of specs or purported superior performance modes.

And finally, my contribution to a happier world;  YMMV      :)