To be more clear:
Instead:
"Using cables longer than 10ft exposes your amp to electromagnetic pickup of everything below 10MHz"
should say:
"Using cables shorter than 10ft protects your amp from electromagnetic pickup below 10MHz"
My logic had better days. Russ69, sorry for posting on this thread. Just wanted to help. |
Frogman - nobody is talking about complete picture but rather about step in right direction.
As for the wire and interference. Lets for a moment assume that we're talking about speaker cables. Interference, usually high frequency, can be capacitively or electromagnetically coupled. In either case length of the wire makes difference. Let assume further, that we're dealing with electromagnetic pickup. At very high frequencies output of the amp has high impedance being also an input since feedback i connected there. Cable becomes an antenna. Antenna becomes practically ineffective when it is shorter than 1/10 of the wavelength. Let assume that we're dealing with 10MHz radio station nearby. Tenth of the wavelength is about 10ft. Using cables longer than 10ft exposes your amp to electromagnetic pickup of everything below 10MHz. It is not big help for very common 10ft cable since there are many radio stations above 10MHz, but at least eliminates a lot of mid and shortwaves. It can also eliminate other sources.
Reverse situation. Imagine that your class D amplifier is polluting speaker cables with 0.5MHz frequency. In order to effectively radiate it cable would have to be 200ft long. Your ICs can still pick it up capacitively but most likely they have shield and are in some distance.
I don't know of any positive effects of making cables longer. It will only introduce more interference by extending bandwidth increase capacitance and inductance. Unless you believe, that cable "enhances" sound longer cable is worse cable. 0.5m IC is better than 1m IC in spite of what dealer tells you (he has 1m in stock). Exception is digital cable when you want it either very short (few inches) or at least 1.5m long (but not much longer) to avoid first reflection on impedance boundary to interfere with the edge that is producing it thus affecting clean transition thru threshold point causing jitter (noise in time domain).
Even shielded cables are exposed to electromagnetic pickup. Non-magnetic shield (aluminum foil, copper braid) in reality does not protect against electromagnetic pickup but picked up signal, being high frequency travels on the outside of the cable - shield, because of the skin effect. Effective field in the center (where wire is) is zero. Skin effect is diminished at lower frequencies but they won't be picked up unless your IC is long enough to be 1/10 wavelength antenna. That's why even shielded cables should be kept short. |
I posted this in another thread, and thought it was relevant here.
****I know this is a crazy question but is it possible that the length of dissimilar conductors with varying dielectrical properties can have varying effects,positive or negative,in terms of introducing,eliminating,or altering interference?**** - Fripp1
I don't have the slightest clue. But your comment suggests something that is overlooked by many on the "numbers" side of the isle. We crave answers and explanations. But why are we assuming that we are asking all the questions that need to be asked? In my estimation it is short-sided and arrogant to think that established electronic-design standards address ALL that is going on in an electrical circuit. Is the science community not regularly discovering new things,and debunking previously accepted notions? Why should audio/electronics be any different? Add to this the fact that we are not talking about race cars or wine. The affected "product" is being asked to deal with the reproduction of an ART form. Complicating matters is the fact that we are talking about an art form that is not static (some visual art). Music is not only a constantly moving target,it has as a core ingredient the expression of emotion,and often involves the sonic result of human interaction. To think that numbers as understood today can be a complete picture of what can be going on in the electronic record/playback realm,and how that might affect our perception of it is silly. |
Onhwy61, the analogy with motorcycle racing is one I must applaud you for!
This is the argument I've been making here and there on this site over the past year or so. Quite simply, the move of measurements from algebra to calculus.
Previously, in motorsports, the means of measurement you enumerated dealt with the steady state - algebra. As you also noted, because of the intense competition (and available processing power) they were forced to transcend that realm of operation, and now deal in the real time measurement of acceleration/deceleration, forward/reverse, stop/start, etc - calculus. At that point, folks are able to digest this data, make adjustments, and ultimately implement things which yield tangible benefit to the craft.
It would be nice, as you say, that this transition also took place in audio. Unfortunately, I must say that I am not as sanguine as you are about how this will proceed in our niche. In my opinion, with few exceptions, this lies beyond the ability/capability of the designers currently in the high-end audio hobby. |
Onhwy61 - I'm only saying to avoid products that measure too well for the price, because something has to give and often it is sound. Soulution monoblocks look very impressive but I'm more withing Rowland 625 range.
I agree, that some kind of dynamic test would help not only designers but also buyers to make right decisions, but so far I can see many key specifications missing or without reference point. We all learned, one time or another, that equipment tested with sine or square waves behaves completely different with music. Often not a good specification but rather company name is wort paying for. I ended up buying small Rowland amp knowing that Rowland for over 20 years produced only very good amps. My next amp is likely to be Rowland.
I'm all for better testing, being frustrated with trial and error while pieces are often not available for trial (heavy or expensive). To add insult to injury some dealers start charging for in store demonstration. Well, it is what it is. |
Trelja, this may not be that coherent an explanation, but this is what I'm thinking...
A generation ago the engineers and tech involved in grand prix motorcycle racing basically had a stop watch, temp gauges and the comments of the rider to tell them about the race track performance of the motorcycles. With so little information the rider's comments about feel and responsiveness dominated the motorcycle's development. Today the situation is vastly different. With multiple computer setups data is streamed in real time or downloaded for analysis. The rider's comments are still important, but they are not necessarily the most important source of information about how to get the bike around the track faster. The better race teams have learned gather and make use of the data.
I think we're at a similar point in audiophile equipment design and manufacturing. We no longer have to just rely upon our ears and a seat of the pants explanation of what is going on inside the components when they are playing music. We're no longer stuck with static test signals and can now actually observe circuit behavior under dynamic conditions over time. At least that's what I am led to believe from reading manufacturers' papers. As an industry we're moving beyond frequency response, THD and S/N. I think that's a very good thing, but at the same time it doesn't guarantee better sounding components. I do think that over time the improved analytical capabilities available when used by skilled engineers/designer will eventually produce better components. We're always going to have to trust our ears, but we're also going to have to trust the measurements too.
Kijanki, from reading your posts I think you know way more about electronics than I ever will. I acknowledge that and I respect you for that. However, when you say that you should avoid products that measure well -- I just have say that don't make no sense.
As far as Soulution and NFB -- some of their product blurbs say they don't use it and at the same time there are printed comments from their designer saying he's taken heroic measures to implement high speed NFB circuits into the product. |
Onhwy61, "I think the audiophile world is on the verge of what might be a significant advance in sound reproduction quality as engineers are becoming more knowledgeable about what to measure and how the interpret the data."
Can you elaborate on that, please? |
Onhwy61 - Rowland amps sound great because of Jeff Rowland and not any measurements.
Atmasphere amps measure quite bad (THD=1%, DF=1) but sound great.
I don't want to go into details why "feature massive use of negative feedback, outrageously good measurements and supposedly outstanding sound quality" isn't possible, but if you think of soulution 710 amplifier then you're mistaken. This particular amplifier has zero feedback:
http://www.axissaudio.com/amplifiers/710.htm
It is also mentioned in 6 moons review that 700 amps have zero feedback. Anything can be designed. The issue is cost ($40,000).
Icepower that you mentioned measures average. Popular 1000ASP module has only 38kHz bandwidth, 60deg phaseshift (20Hz-20kHz) and 0.2% THD |
Kijanki, a well crafted telling of the standard audiophile dogma with just a hint of hyperbole. But is it possible that it's not large amounts of negative feedback that's the problem, but instead the careless or sloppy use of NFB in circuits not optimized for large amounts of NFB? You should read up on the design criteria for Soulution amps/preamps. Their products feature massive use of negative feedback, outrageously good measurements and supposedly outstanding sound quality. I think you need to rethink your opinion about NFB.
Leaving the world of NFB behind, my earlier point was to point out that science (measurements) is best used in the design of electronic equipment intended to reproduce music and emotions are best employed when listening to music. I think the audiophile world is on the verge of what might be a significant advance in sound reproduction quality as engineers are becoming more knowledgeable about what to measure and how the interpret the data.
One last point, Rowland amps, even the ICE-based ones, measure quite well. Come on down from them hills! |
in addition to bach, i would include purcell, scarlatti,froeberger, and other composers who wrote harpsichord music during the baroque period as very helpful when thinking is the sole activity. |
I feel that Mrtennis invokes instigated contrast to fuel his narcissist mentality.
He canÂ’t help it of course, but we all can. |
mrtennis
Perhaps the well tempered clavier stimulates the left side of your brain, without necessarily introducing any conscious perception of an "emotional" response?
A perfect cappucino in your favorite cafe might evoke an emotional response, but caffeine by itself is only a stimulant?
What other composers or music, please, would you recommend to enhance concentration and/or to prove that all amps do not sound the same. |
Mrtennis, you are welcome. In answer to your question: Yes, I believe that
all music evokes an emotional response; anything that can fairly be called
music. It may not be a positive or pleasant response, but a response
nonetheless. Earlier you wrote that there is music of the brain, cerebral in
nature, and that does not necessarily evoke an emotional response. You
cited TWC as an example. Later you write:
***people are different in their reactions to music. i find the well tempered
clavier very helpful when solving mathematical problems.***
What is it then that causes this "help", if not an emotional
response?
BTW, a common discussion among musicians and musicologists is the
notion (by now, fairly well debunked) that Bach's music, particularly
TWC, is to be performed in a cold, mechanical (mathematical) fashion.
Not so. Additionally, it is also an accepted idea that in Bach's time a
tempo marking was an indication of the intended emotional character of
the music ("Allegro"). |
"but if you want to electronically reproduce music, then the measurements should be the dominate method of understanding."
Onhwy61 - In order to get pleasant sound from SS amplifier you need to elimnate TIM (transient intermodulation) distortion that enhances odd harmonics and cannot be easily measured. This TIM is created by negative feedback - same feedback that makes wide bandwidth, low output impedance, low THD and IMD. If you see extremely good measurements - run away. |
Measurements vs. senses is a false dichotomy. True audio reproduction art sensibly merges the two drawing upon the respective strengths of each area. Your physical senses cannot tell you that the earth is rotating on its axis and circling the sun at speed greater than 1,000 miles/hr. You have to trust measurements to understand those facts. At the same time all the math and measurements in the world won't help you consistently hit a curve ball. If you want to listen to music, your senses should dominate, but if you want to electronically reproduce music, then the measurements should be the dominate method of understanding. |
hi frogman:
thanks for the link. people are different in their reactions to music. i find the well tempered clavier very helpful when solving mathematical problems.
the intricate harmony has an affinity to mathematics.
granted, i may have an idiosyncratic response and be in a minority of listeners.
|
I was about to say that of course they all sound the same -- right up until the moment you plug them in and start trying to reproduce recorded software with them -- but then it occurred to me that even at might not be entirely correct..... |
|
All people look the same, all crap smells the same, all cars drive the same, all people sense the same, all opinions are the same....just thought everyone should be reminded.... |
hi frogman:
does all music have to evoke an emotional response ?
i think some music is cerebral in nature.
have you listened to bach's harpsichord music ? if do, what emotional response do you experience?
there is some harpsichord music with intricate harmony which could stimulate the cerebrum.
i think you are a bit dogmatic when you assume that all music evokes an emotional response. you are not taking into account differences among listeners as to how one may respond to music. |
Isn't the ability to evoke an emotional response what distinguishes art from craftmenship?
and its different in every person. To someone maybe death metal brings back memories of a better time and brings one to tears while others think its noise. We also want that moment to sound to us the best it can.
I do not read an amp or study it based upon its numbers. I listen to it to form my opinion to see if its something I enjoy or something I don't. If you want to use math all the power to you. Numbers are numbers, my ears are what I use for music listening, I would rather trust them to pick the sound I like the best then reading about a number of paper. |
Isn't the ability to evoke an emotional response what distinguishes art from craftmenship? |
****music need not induce an emotional response to be enjoyable.****
It is clear that when it comes to art, some of us live in different universes. Maybe that was a bit severe...different planets.
Venus and Mars |
If a tree falls in the forest and no one is there....... |
music is about the brain. there is plenty of music which is cerebral in nature, e.g., bach's well tempered clavier.
music need not induce an emotional response to be enjoyable. |
hi russ69:
you are right about ears as an instrument, so long as you acknowledge that what you hear does not constitute knowledge, and what you hear is an opinion.
what you hear or what i hear cannot be proven.
what one hears is neither true nor false. it is also not a fact. |
I understand fully what MrTennis is saying but in audio the only tool we have is our hearing. It's not a perfect situation and two people can disagree about what they are hearing. That's basically why long term evaluation is relevant to our hobby and DBTs are not.
No piece of equipment has been able to deceive my senses in the long term. Yes the senses are unreliable for recording instantaneous events, I'll agree with this but the ears are good instruments and in this case the only relevant instrument. |
Frogman wrote: music is all about emotion and the senses. The technology...has to honor that fact... The numbers must always take a back seat to the senses. One has to trust one's senses and emotions. That is what gives all this true meaning. I nominate this for "Post of the Year". The ONLY thing that matters is how the performance you are listening to affects you/sounds to you! |
I use ROWLAND 8T 250ch sounds wonderful. |
Perception and reality come together if one of the two condtions are met:
1. Two or more people agree on what they saw or heard.
2. The President of the United States says it is so. |
the senses are unreliable. witnesses to an event often present different versions of an event.
what you hear one day, you may not hear on another.
there is a myriad of experiemnets in the psycholgy journals, which discuss the unreliability of perception.
when you trust your senses, the result is probably true and probably false.
most audio discussions are philosophical disccsions.
they have no definitive conclusion.
let me give you an example.
suppose two people are auditioning a stereo system. the evaluation by each one will probably differ, one from the other.
in my hypothetical example, it is impossible to determine which assessment is true and which is false.
in fact "truth" and "false" are hard to establish in these audio discussions. |
****my point is that one should not trust the senses****
Mrtennis, I truly admire the steadfastness of your very didactic approach to things audio (and, I suspect, other matters as well). But, I can't help but react to what is probably one of the most provocative statements that I have ever read in a music/audio forum. Not trust one's senses? Huh?!?!
This points to what I think is one of the key underlying issues in disagreements among audiophiles; disagreements about the merits or flaws of equipment, design concepts, and the technology of music playback in general.
What I refer to is inextricable connections between the humanity (senses) of the performers of the music, the humanity (senses) of the listener, and the techno-quagmire (audio equipment) that is a kind of necessary evil along the way. The senses cannot be ignored, and most definitely should be trusted. I suppose this all points to differences between different types of personalities, but music is all about emotion and the senses. The technology used to capture it and play it back has to honor that fact if it is to be truly successful. The best audio designers know this. The numbers must always take a back seat to the senses. One has to trust one's senses and emotions. That is what gives all this true meaning. |
"hi russ69: my point is that one should not trust the senses."
I use my ears, to listen to my HI-FI. I can listen to a pair of amps and tell you which one I like better. It may not be better by measured criteria but I can decide if it sounds better to me. If the two amps under test are very close in sound, then I will have to spend some time with each one. Sometimes a long time. After a while and some evaluation, I can pick the one I like.
I trust my senses, if I have the time to test things out. After all we are using one of our senses to enjoy HI-FI. Can I be misled? Sure, but not for a long period of time. I trust my ears. I surely can tell when something sounds like crap. I don't need any supporting documentation for that. |
hi russ69:
my point is that one should not trust the senses. it's one thing to be confident that there is a difference between two amps, its another to know it and prove it is true,.
there is no valid proof that is based upon sensation.
sensation is a form of opinion in that there is a probability that the sensation is true and a probability that it is false.
all statements which assert superiority of one component over another , or an attempt to describe the sound of a component can not be knowledge, hence they are probabilistic. |
MrTennis, I've never read anything in a spec sheet that gave me the slightest clue on how an amp sounds. I'm not sure we are even measuring the right parameters.
No, Jedinite24, just can't understand why somebody would make that statement unless they have just started in HI-FI or never had the bucks for a good amp. Just a discussion, that's all.
|
hi rodman. you're right but you have to listen to an amp to hear it. the fact that you can measure them , does not constitute a proof that they "sound" different. |
Mrtennis- How does Math, "sound?" (just kidding) I know Acoustics, Electronics and gear specs are all about Math, but- ANY two amps are going to differ in SOME measureable parameters. |
Some people like a Timex because it accurately and reliably tells the time. Some people like a Timex because it shows they are pragmatic and sensible in how they spend their money. Some people like a Rolex because it has a nice weight and feel on their arm and will look like new 10 years later. Some people like a Rolex because it shows they have discerning tastes and the money to support those tastes. How does that compare to amps? Well, some people like their MP3 player because it can hold thousands of songs and play them forever anywhere and everywhere. Some people like their lower cost amp because it shows that they are pragmatic and want reliability. Some people like very expensive amps because it shows that they have discerning tastes and the money to support those tastes. Some people like their expensive amps because the sound is what they have been searching for since forever. And owning it means giving up something else.
You know what is a real waste? Someone who drives a Porsche just to commute to work. This is a car meant to be driven, driven by a driver with the skill to appreciate it. Comparably, a hifi system purchased by someone who does not really listen and appreciate the music it can make. To say all amps sound the same is simply someone who has not yet listened, or heard the music different amps and systems can make. |
the statement "all amps sound the same" can only be proven mathematically. while it seems intuitive that the statement is false, a definitive proof is necessary.
relying on sense perception is invalid because the senses are unreliable.
can anyone offer a mathematical proof ? |
I haven't done direct A/B comparisions in my listening room. But, my guess is that at least some of the affordable multichannel amps from Yamaha, Marantz, Denon and others are competitive with the audiophile offerings of smaller manufacturers. Particularly with speakers that are easy to drive, which is the current trend in speaker design. After all, do people really believe that a Jaguar outperforms a Honda, or that a Rolex outperforms a Timex? |
I think whomever posted the stuff in the OP was just trying to start a fight or rile up folks. |
IMO comparing an amp to a mutlichannel AVR is not anywhere in the same area.
The statements the OP posted to me come from someone not very fimilar with the hobby like we are.
For instance it would be a tough day for an AVR to drive certain speakers and I think one would be asking themselves why does my AVR blow up when I choose to run a 2 ohm load on it?
The box stores like Dumb Buy and alike push AVR's as that is what most people go in looking for. Even HTIBs because someone can't even understand the difference between an AVR and a HTIB.
That and when people are listening to crap thru bose systems what would they know? They think they got the best out there due to name. Heck I even work with a kid who was a Bose store manager and tells me I'm stupid for buying audio like I do.
In the end, to each their own. I wish more people could wake up and hear what good SQ is like but then that would mean they would have to take the time to listen in such a busy world. |
If all amps sound the same, then we should recommend that everybody buy a 500 watt a channel job as their first and only amp they will ever need. How come the guys that think all amps sound the same never own/owned a big/expensive amp? |
Jeff_jones - it is not that simple. SS designs 50 years ago were horrible with huge negative feedback and a lot of TIM distortions. Sanity is slowly coming back but amplifier design is not a trivial thing especially with budget constraints. The fact is that even for $1500 today you can find very decent and very horrible sounding amps. We tend to prefer the first kind. |
If all amps don't sound the same now, when will they?
I.E., board level components are cheap, excellent designs have been in existence for more than 50 years, even the more showy items such as heavy metal structure & etc. become a minute contribution to price once the price point hits a fairly modest mid-fi price level. What is there in the production of a world class amp that would justify more than say a retail price of $1500.00 for absolute state of the art performance?
There is the thing about some preference for NOS tubes come to think about it, so perhaps the rhetorical question would need to exclude high dollar NOS tubes or other bits of unobtainium that I'm overlooking. |
Most of my friends believe that all amps and CDPs sound the same (it is only about power while digital sounds always the same). Interestingly, they believe that speakers make big difference. 33% success rate ain't bad. |
09-05-11: Rok2id
maybe 'all audiophiles sound the same' would be a more accurate ststement. Not in a million years !!!!! |
maybe 'all audiophiles sound the same' would be a more accurate ststement. |
Audiofeil, no, no, no. Every power cord sounds the same, it's the wall socket that makes the difference. :-)
Below is a scene I'm writing from "A Few Good Audiophiles". (Any similarities to "A Few Good Men" is purely intentional).
Jack: You want the proof?
Tom: I want the proof!
Jack: You want the proof? You can't handle the proof!
Jack: Son, we live in a very electrical world. There are things that go on that you can't possibly fathom. I offer the security of a well made wall socket so that you can sleep at night under the blanket of knowing that you are getting the best sound possible. Deep down, you WANT that socket in your wall. You NEED that socket in your wall and I resent you even questioning my authority about the way I go about it.
Jack: Are we clear?
Tom: Crystal. |
Unsound, the easy solution to your statement is to go active and eliminate the passive crossover which imo is a dinosaur anyway. Now you have serious sensitivity with the ability to precisely tailor response. |
