--------------------------------  Uncomfortable truths ---------------------------------


A few lines to introduce myself and to describe how the passion (perhaps sometimes excessive) was born for the reproduction of music. I was born in 1964, I bought my first magazine in 76 (at the age of 12!) from which he began to grind the "worm". Two years later my father was forced by the stress I caused him to buy my first implant. It was a Pioneer coordinate, turntable + integrated + coffers with a total value of about 350,000 lire. The following year I had begun "erosion" to my mother's patience to replace the speakers with the glorious B & W DM6 I had fallen in love with after a comparison in store with the Allison one and the AR 10 p Greek. In 1979 came out the first series of B&W 801 acclaimed by the magazines and I "forced" my mother to take the train journey Ravenna-Milan to accompany me to the exhibition for listening to the 801 compared to the DM6. The trip was profitable: the DM6 I liked the 801 no! After the purchase of the DM6 (which only very much later I replaced with the ESL63) the changes in the system have been proportional to the increase in age (and economic independence). At the same time I had built a 10watt amp with a scheme taken from a magazine and without any pretense. To my surprise this little box sounded much better than the SAE 2400L final I had at the time. Trying to build a second one, the result was no longer the same: some variable had influenced in such a way that the same pattern sounded very differently. After the studies (electronics) I decided to go into the ambitious project of an extreme power amp: high slew rate, low feedback factor, class A, strong current supply capacity. Thus was born the first version of 100Watt mono but compared to the 10watt power amp here the surprise was against: in the face of excellent instrumental measurements and much more ambitious pretensions I found myself faced with a very bad listening result! After more than a year of intense work, it did not make me happy, but it made me understand a fundamental thing: the truth was not in some theories sold as sacred, there was something else, perhaps not yet known but that caused certainly an enormous degradation to listening. Here was start my personal research on "cause". It was the year 1984.

A research based on a scientific method, then repeatable: we observe the fact, we create a working hypothesis, it occurs in practice and if we find that a theory is valid that is valid until it is invalidated by a subsequent hypothesis-verification. Many time was served before understanding where it was generated and how it interacted with listening to a particular phenomenon and I do not deny having had moments of depression when in front of a huge amount of work I could not "remove a spider from a hole", however, in the end I managed to elaborate a systematic theory to intervene on this problem.

We will resume this topic in the following paragraph that deals with the amplifications, but let's see before tackling some other inconvenient "truths" or discounted truths, if you prefer. In fact, there are many aspects whose validity is taken for granted in this sector. Personally, however, I am of the opinion that those strident aspects that can be identified in many of these "truths" need to be addressed without reverential fears. There is nothing worse than basing a project on wrong foundations but which are considered valid and therefore untouchable. The main quality that should have a good researcher, in my humble opinion, is always to question one's own choices and the goals achieved to reverive both of them several times in later times.

The choice: Sealed or Vented box ?  
For some time, are always looking for more fans like Rogers LS3/5a 15ohm speakers, Dahlquist Dq10 Grundig (largely because of this

site...) and to a lesser extent of other speakers (B & W DM6, Gale gs401 , Lean type A, etc) whose project starts from a common root: the air suspension. All of these speakers actually have the woofer that works in sealed box. How does this choice on the final result and why over time it has abandoned this solution? Assuming you want to get a full-range speakers, that is with an extension in the low range of 40-50 Hz with a-3dB, with the same frequency extension in a sealed box woofer needs a size twice that of working in a double volume than a reflex. A woofer that does not lend itself to the construction of a 2-way but it forces the use of a midrange, and then at least the construction of a 3-way. The possibility of obtaining a full-range speakers in small size and using only 2 speakers was a spring enough to supplant the "air suspension" in favor of "bass-reflex". Any cash resonant inverter works as a phase in the response that this resonance is to take effect ... but if we go up to frequencies beyond doubt from that area no longer effect "spring" of the resonator of Helmotz and the speaker assumes connotations that make it similar to a sealed box (which is detectable by both the frequency response of the cone dall'escursione at these frequencies) with a difference: reflections on the interior walls that remain confined within air suspension chest (as well as attenuated by absorbing huge amounts of noise) in a reflex to find "open door" to get outside with phase shift that depends obviously on the wavelength of the signal being played. This causes an inevitable dirt in the mid range and are certainly not the only one to say it, see here . If you do not like the speakers currently in production a large part of responsibility is due to this "foundation" of fashion called bass-reflex.
Full range, two way or multi-way ?  
We come now to some considerations on whether to use one or the other of these systems by analyzing the pros and cons.
Full range: ideal from the standpoint of power because it uses crossover, involves insurmountable problems from the point of mechano-acoustic, in fact if you try to have a very light rotor will extend the response at the top but the bottom will be limited greatly (Conversely overhead cone) because the air resonance of the loudspeaker is given by formuletta fs = 1 / (* root 2pgreco CM) where C is the softness of the crew and mobile M is the mass. If we add that to avoid the problems described above is necessary to eliminate the wave back by putting the speaker in sealed box (thus further raising the resonant frequency), we get an end result greatly restricted in the low range.
2 ways: by Multi deserves distinction: it has a good thing to represent the best compromise between the extension and limited frequency interference between speakers. Appropriately treating consistency at the intersection, you can succeed with sufficient fidelity to simulate the benefits of the single screw without having the disadvantages.
Multi ways: ideal as an extension of frequency response, has its main limit the interference between the speakers with crossover frequencies (but also increase the problems of diffraction and phase ...). And 'what is evident listening to even the best Multi-channel I happened to be (coincidentally Grundig) compared with the two-way (Grundig Box 300, SL1000, LT DSL): In front of a dynamic and an excellent frequency extension, but also a tonal balance out of the ordinary, it still shows a lower capacity to disappear

Speakers identical or mirror?
I refer of course to all systems where the speakers are mounted to project requirements, but not aligned side by side raising the question whether to make the two speakers as the mirror image (that have a left and a right chest). Let me try to dispel this myth which is another result of the hi-fi ruminations mental rather than actual verification plays! Personally I have had three occasions to see how in fact the best solution is to have two identical speakers (ie non-specular).
1) Direct comparison between Dahlquist DQ10 and DQ10 improved: exactly the same crossover and speakers, the only variant of the arrangement of the mirror speakers (left and right) of improved
2) Direct comparison between 850th Grundig box and a version of the same with mobile rebuilt (maintaining the same speakers and crossover) to get the mirror mounting and mr tw.
3) Installation of a pair of Magneplanar MG II where the comparison was done by rotating duplex speaker to address the specularity of the installation normally.
In all these circumstances, the mirror version had a more sound off with a 'more compressed image and a much poorer instrumental timbre harmonics (which causes a hardening of the sound than the version with the same speakers for both channels).
According to what I have heard it seems that the stereo expect to have two identical sound sources in which the auditory perception of sounds that makes the sum of the individual speakers. Specularity is interpreted by the auditory system as a form of distortion of the stereo.
Amplification: valves or solid state?
Read this section with particular attention!
I would say that the first question they ask is meaningless: depends on what the sound of an amp? You will find fine technicians who will tell you (with technical explanations to follow) as the zero feedback is essential, some is critical intensive use of feedback, others will tell you that it is essential to the valve (or maybe a monotriode bell'OTL. ..), some MOSFETs, other class A, etc etc .... but the crucial point is: if the person who tells you his "truth" is right, that is, his theory is true and can actually solve the problems you normally listen to, he must and I repeat must be able to build models of different amplifiers with different powers that they play together almost indistinguishable as they do not have their own features and therefore with a much better harmonic freedom of others ..... at this point you wonder: will you ever find something in any of trademark? If you are honest with yourself the answer is no. Within the same brand you are always faced with sometimes very different sounds, or if there are paradox is only similarities in the face of sounds overly compressed (ie, no harmonic content). There are occasional (and rare) cases which were found in a model (and only one) X brand of musicality but certain features are not replicated in other models of successive series even at the cost of major project efforts, some cases are obvious For example, the Class DR3B (also in the VHC) or the Pioneer M22: no other extension of such brands has never sounded like these two models...so what is the state of the case and the calculation behind such sounds ? Personally I have heard good and bad valve valve transistor as good (though more rarely) and bad transistor, but what remains is really rare to hear an apparatus which is excellent not just good, something that manages to bring through the speakers developed in three dimensional space where the instruments will detach and maintain their harmonic content and therefore their stamp. This is because to build something that stands out from the sea actually do not need to improvise the ordinary construction of this or that circuit using the best materials and oversized everything, as is being done today boggling prices and increasingly deleterious results for music but serves only one thing: to understand why. Can you imagine a designer of F1 was not aware of what rules aerodynamic design? Must therefore understand the real reasons that cause these significant differences in listening. Serves as a consequence an element that currently very few brands can afford: time to perform a specific search ... which in turn corresponds to money, a lot of money to fund research that can take away years. For a search like that should be at least a 'multinational industry (I'm thinking about the size of Philips or Sony) but none of these brands would dream of investing large capital to satisfy four cats scattered as are the current high-end enthusiasts, it would be an investment certainly failed. Could have been done at the time of booming hi-fi, I'm talking about the 70s, where a possible large investment would lead to least likely economic return, but ....... and if there had actually been? If any of these big brands had brought forward a great deal of research quite muted and the obtuseness of certain press "specialized" if he had not even noticed at all snubbing brand products in question? Well if you have a little 'patience and you are among those who seek the truth even if it is hard to digest at the end, you'll discover a gem that will make you happy.
The alternative to big industry to conduct this research is to those who should not be paid for the time it takes on the work as "craft manufacturer (other than the fact dall'autocostruttore copy patterns and / or existing equipment). What do I mean as a "builder craft"? Simple, a fan with a thorough knowledge of electrical phenomena and electronic willing to spend the time necessary to understand why. Here the danger is only to be considered autoappagati maybe not seeing that the goal is still far away so you should always be as objective listening (then "detached" from its creation), as the only opportunity to check to make progress.
One who knows the answer to the question "On what does the sound of an amp?" is able to play the same way a final valve and a final transistor and to a level far beyond what is given to us to listen to the community and then not need to use the valves with their problems (heat, wear, microphonics, output transformers, etc.) but we have a transistor amplifier that looks like it 'to a tube it' to a transistor but which will make us dream. Unfortunately, the design of a product sound good is challenging, can take years of research work and only if such work is done with passion, seriousness and with no hurry to reach the end come the results.
... about the gem is called GRUNDIG but do not try the products currently on the market, the real Grundig went bankrupt in the years 86-87, but before that date to begin the products produced by 74-75 years have used a specific research that has given a very real answer to that question and I assure you .... it feels! I know that most of you think strange in front of a famous brand for TVs and radios and not the hifi but the team of engineers from the German house knew a lot in that regard .... very much more than would be expected and this was combined with a guideline to the quality of the brand incredibly face of even the slightest particular product (and how sustainable production costs only in the face of enormous quantities produced ... which is possible only in the boom years hifi). Personally since I started working in design (a summary of my personal story can be found here: webmaster) and to find my own answer to this "because" I have in years of work, created beliefs that were reinforced when In 1990 I met the products of the German mark. Looking to get straight to the point I personally have found only two cases that have real influence on the sound of an amplifier:
1) the frequency response and sometimes change a few tenths of a dB are audible in systems with good transparency harmonic
2) The problem I have baptized in 2004 CCI: Circuit Chassis Interface which is due in full with the harmonic freedom of an appliance and differences between devices with the same linearity of frequency response. and which is found in products applied to the German house of that particular decade. Totally numb my ear is evidence against harmonic distortion of 5% as well as those outlined on the actual load test here a Class D measurement.
For those struggling to understand why these devices should be as diverse CCI, dated 10.11.2003 with a post made in a popular Italian forum I decided to disclose a particular (whose influence known since 1980) that causes a change exclusively in the field to enable CCI to understand how this phenomenon can affect on your system: to remove testing by VS. electronic (CD player, pre, final) the top cover (only for test then obviously reason to call for security reasons ......), you will notice a significant change in sound that great improvements in terms of airiness and tonally might even get worse (by making more highlight the problems of the rest of the chain). Remove the cover from the viewpoint of harmonic freedom is always a general improvement in all units, while CCI is not a significant deterioration exclusively on devices that CCI and optimized chassis, however, are obtained for this performance far beyond those obtained by a non-CCI "uncovered." For those who think of electromagnetic problems by replacing the lid with a plastic differences remain however different ...
To avoid misunderstandings: The comparison between the lid must do so well screwed (and not just resting) and lid removed.
The accounts if you notice begin to include reporting back to those two examples of amplifiers (M22 and DR3): both have a frame of "particular" that by chance (in this case with no awareness of any consequence but to have to solve problems dissipation of Class A) partially solves some problems related to the ICC to smooth and enormously different from other amps of the same brands, the sound of these two devices. Are not the only cases of partially amp CCI, others I know (mentioned here: major appliances) as well as many others surely there will be among those who do not know .... but you can not get chance to have an amp full CCI.
For those who think that an operation must be represented by counsel in class to listen to other Class A (Krell, AM audio etc) to make them readily account of what the sound is poles apart from those.
Deliberately not going to dwell on the causes because I personally am over 25 years working on various aspects of this problem.
Warning: the above does not have anything to do with the electromagnetic properties of materials (and related forms of distortion resulting from already discovered in the years 70-80) and within the CCI has an influence on the periphery.

Here my products.
CD player: how many bits ?  
Springs to mind the story of such a Linn who objected to the fact that the turntable would sound alike because they were not directly traversed by the signal. E 'state (at least for the general public) a runner in unhinge some "certainty" that held sway until some time ago. Now there is news that a turntable sounds different from another, same thing happened to the presentation of the compact disc. The magazines in chorus: "Finally a source that will play in the same way!" Soon even this certainty has been demolished by creating another equally false and that attributing the differences in sound of the converters and the mechanics of the laser. Too bad that even pre and final exhibit significant (and similar) differences in listening ... without having a converter or a mechanical laser! Does not teach anything that?
"What? You still have a converter to 14 bits with sampling four times? Poor fellow, I have a 24bit high-precision clock 192kHz and is dedicated entirely different thing." Another "convenient untruth" but unfortunately supported by all as they should on the market. Imagine for a moment what would happen if it were proven guilty (which is not difficult to do ).... the market for CD players would be paralysis.
And to think that disc is engraved on the poor "words" encoded at 16 bit and already at the time of Philips CD100 by using four times oversampling coupled with a 14-bit converter is obtained (it was mathematically proven) advantages in terms of solving a 16 plus a bit milder filtering extreme high that allowed for a linear phase response (as noted by the impulse response), yet ....
The differences between different readers are always present but completely independently of the 'unit conversion but simply for the very same reason that you will never find two preamps that sound alike or two finals (except CCI) while presenting a similar frequency response!
The problem that afflicts the sound is very different nature and with the unit conversion got to do like a khaki snack ... it all comes down (assuming you have the same frequency response .... do not give way to discount ...) to a different interface chassis, high frequency that determines therefore always a different sound depending on the frame adopted and this even at the cost of using the same converter and the same mechanism. Who has heard the player Roadstar 20-euro mod. CCI compared with the same model number or comparison of its CD player ESO knows something ....

.... or as you want at all costs try to validate theories that have no feedback with practice in full anti-scientific attitude.
A misunderstanding of the basic design of the turntable is to infer the acoustic feedback as the main responsible for the sound of the turntable itself: something absolutely false, that does not find any (even minimal) response to listening.
Any suspension is able to provide sufficient insulation to the demands from the supporting surface at least to the middle and upper and middle frequencies while remaining in place for any turntable feedback "direct" on his arm and that is due to the shock wave sound, which directly affects system arm / cartridge that is always present and usually much greater (at all frequencies) as that which comes from the suspensions. It is one thing and then the feedback (to which the turntable has to be adequately insensitive) well other account is the sound of the turntable as is being defaced to be supported by some exaggerations esoteric. The key now is the absence of generalized foam pad that (properly shaped, very important) is a key element to damp the micro-vibrations that vinyl has when in contact with a flat plastic disk (as today goes rage .... since industrially produce a foam pad for low quantities at a cost far greater than that used for turning a piece of PVC ......). The high fidelity today is not based on what is best for listening but what you can make believe it is better to please the eye ...... people meditate and above all .... listen!
The high efficiency

..... and its monotriode which is often associated.
Everything starts from a true account to which (unfortunately) if they associate other patently false ....
What is obvious to anyone with ears (and not know the ICC ....) is that the sound of an amp on average is better (read more graceful and harmonious), the lower is the maximum payable by this amp (in this As the "problem" that must be balanced the depletion of which I speak on the "inconvenient truths" worsens proportionately with the power). At this point someone has thought well to combine equipment from 1-2 watts to monstrous efficiency horn systems ..... getting horrible results in terms of colors ...... but with so much "scene (ehm. .. but no visual noise ...).
Even the choice of monodispositivo active (monotriode) is per se wrong because despite being a device that allows reduced power supplied also has the disadvantage of having a reduced open loop gain (and therefore impossible to apply an appropriate feedback) and high impedance output that causes the effect "roller coaster" to measure the frequency response on real load. Would serve to achieve a linear response multidevice amp (tube or transistor does not matter to these powers ...) but this would still collided with the intrinsic nonlinearity (and does not solve ...) of the high efficiency .. ...
Short, even in this case "in medio stat virtus."
Toroidal transformer
Cult objects and deemed a "must" for the construction of apparatus of "true high fidelity" is ....... but one of the more responsible in terms of the components used (and therefore equal presence / absence of CCI implementation ) sound dry and impulsive behavior.
When I think that the manager of a Polish site edit an amp Grundig CCI replacing the transformer with a toroidal have a measure of how the conditioning technique makes dull listening!
The ferrite core of these processors due in fact a spurious radiation of AF (caused by the "team" this classic on the secondary wave due to the capacitor charging current through diode bridge) but very much higher than normal processors which consume sheet with non-oriented crystals. This results only minimally screen since it is precisely these spurious to be present in both the higher secondary (by induction) broadcast to the primary of the transformer more interesting then the entire power grid of the house who is behaving like a true and his antenna!
This info you will not find on any website but I think (being precisely from these considerations that started for me in 83 developing what I called then ... CCI) can be helpful to some manufacturer / builder hoping at least avoid " massacre "by some who want to" improve "appliances, however, are almost perfect as-is (Grundig CCI).
I should point out that the statement is normally measured and yet ....... it seems that the spurious AF still can not import the "lords" of high fidelity, or believe we can solve with some filtration END .... but unfortunately is not.

That is, as sometimes cause huge changes to the sound of the system without changing equipment!
Be very fashionable now than several cm thick python and maybe slyly derivatives (eh. ..... the beautiful country) to the power line industry but cleverly advertised and esoterically "dressed" with connectors and girdles that give a certain look "interesting" .
The cable must (second chance "convenient untruth") to be big and flashy otherwise ........ not sell!
Moreover, try to think as you begin to feel a conviction cable resigned-looking, small diameter and without those beautiful gold and massive liners and those who donate to the cable connectors to amenities that we know. A priori lower assessment puts it aside without even listening to it but rather pointing to some kind of sonic abominations! All the rest (magazines, manufacturers and retailers) have an interest in selling how to improve ESO cables thereby creating a market that otherwise would not exist.
Let me turn now to the motives that determine the sound of the cables starting from the basic condition that there is no obvious difference can be measured using a simple measurement of frequency response in audio band on real load!
Well, we know the principle behind the functioning of electromagnetism and to then Speaker: a conductor traversed by current and immersed in a magnetic field is subject to a force of movement.
You do not just think it's the fact that it happens in a magnetic field (certainly less intense than that located in an air gap of a loudspeaker ......) we always immersed continuously since that is ....... Earth!
The cable moves then, each pole is subject to microspostamenti proportional to the circulating current and the fact that such movements toward the opposite for the two poles (negative and positive) we have a micro-variations of the distance between the two conductors, each having a corresponding movement generation current that tends to oppose the cause that generated it, we can say that we will have a compression wave amplitude in transit.
To prevent the cable characteristics should therefore be that the two poles are clearly still together and is therefore detrimental to both silicone is a sheath (even worse) the interposition of esoteric materials (I've seen also use wire wool!) Making it completely free vibrate the two conductors together.
Having a sheathing material yielding helps but not enough, consider also that the cable acts as the parasitic inductance capacity and a natural filter for high frequencies and here I will not go into the issue as relevant to CCI, but would just to say that filtering high frequency caused by a high parasitic capacitance is welcome (do not overdo it on the wire as a high power capacity is likely to send parasitic oscillation in the finale), while it would be a low parasitic inductance.
E 'depressing, however, realize that a simple network of Zobel is sold and paid handsomely as a "miraculous" little box in some esoteric cables .........
To have a parasitic capacitance is high enough to bring the two poles, then with regard to the signal cable to build a reduced overall diameter shielded cable and power cable to reduce the distance between the two poles (well it will be smaller).
As for the only power cables must also highlight the detrimental aspect of the parasitic inductance factor, not insignificant in this case because the burden constituted by the speaker normally has very low impedance (2-8 ohms) and inductance that would be easy because frequency response falling in the high (especially as a low impedance load at these frequencies). For this reason, in addition to the proximity of the two leads come into play that section of the conductor, and being the inductance proportional to the distance between the centers of two conductors will have a much lower inductance than the smaller section of the conductor.
Obviously we need to find a fair compromise between the need to reduce the parasitic inductance and to not increase too much the resistive component of the cable.
As for the power cable must then find a cable with two conductors as close as possible to each other, with rigid sheath (not silicone) with thin copper wire wrapped and twisted (and is exactly as it did the speaker cable Grundig time).
For interconnect cables the shield is important but more important is the rigid sheath and reduced diameter (resulting in higher parasitic capacitance).
Like the cable signal on the cable network 220Volt you are facing one of the most awkward and difficult truth to swallow: the best network cable 220 times you can find no ground wire is usually supplied with the CD / DVD consumer! Impossible (you're probably saying, especially if you have spent thousands of dollars in cables ....) but I assure you that I was able to verify with certainty on several occasions and is by far the cable that allows freer harmonic yield. These network cables are also available as separate components and are terminated with plastic plugs that side wall outlet should not be touched (the lamination of the plug to the cable housing is a big advantage) while side apparatus are only plug 8 that in case you have taken on VDE VS. Simply plug this equipment be mounted on user side.
Then close the speech with some advice that might open up new horizons are faced with a much better result, and above all get ready to open our eyes to certain "convenient falsehoods" spread by those who have an interest in doing this: disconnect all cables ESO in your house on the VS. system and possibly even after you remove the lids from the electronics, replace with the following:
Speakers cable:
Norstone CL150, ofc 2 x 1,5mmq
Interconnect Cable: GBC mod.CA-201, cod.14.1505.00 (1,5mt) version blisters (and not in the bag that comes from another supplier and other characteristics), it is also important not to replace the original plastic connectors.
Cod 14.1505.15 (5mt) and cod.14.1505.05 (3mt).

Power supply cable: cable with plug 8-pole normally available at any electronics store, is preferred a type of plastic plugs with the least flexible as possible.  
With two pennies and a bit 'of work you will see that thank me later :-)  
About CCI equipment such cables should not be completely replaced with cables esoteric penalty huge immediate worsening. Be careful not to commit the mistake of thinking that any cable can be good economic: there are huge differences!  

"Appearance", this is the real limit of high fidelity with which I tried for years to fight although I realize to take a losing battle. In this beautiful passion more so than in other areas is based primarily on being biased by appearance.
A small percentage of people (those who are not fans, "object" but also including a shoebox if playing!) Attempt to verify the facts without listening to be duped by appearances, but sometimes (especially when it comes to Grundig ...) are ashamed to say aloud their opinion not to be regarded as mad as a hatter (and receive various kinds of insults ...) by "right-thinking" that dwells on the forums of high fidelity.
An attitude of skepticism should be applied prior also and especially the high fidelity "eso", which should in turn prove the value of each unit for which we are asked to shell out some (sometimes many) thousands of euros! I would say that if we approached intelligently high fidelity skepticism should be directly proportional to the cost of the equipment: a device costs more than I should prove worth the money spent! Instead what happens in reality? The exact opposite! Rather than cost more than you buy sight unseen ...trust! (so easy to sell smoke ...).
The only advice I'll never stop to give to those who listen with their ears (for those who listen with their eyes do not need any advice, there is always a wide choice ...) is: check check check ... .. All you can check without succumbing to the snobbery and / or promises sold its weight in gold: the facts, only those count!
Dedicated to know that the truth must be captured (in any sector) and...never painless!
There is no truth unless you have the courage to face it in person! 



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