Dear
@clio09 : I don't post that " he said " but that he " thinks " discovered the black thread.
Now, here is the overall discussion/explanations that happened in Agon 10 years ago where Ralph and me were in those threads.
It's a very long dialogue but put true ligth in that " unsolved " ramtubes OPs:
with this ( mine ) post started the whole followed discussions/explanations:
"""
I own/owned and heard all the cartridges named here including your beloved SG and my experiences about were a little different from yours.
First I have to tell that as important is the matching in tonearm/MC-MM cartridge as important is the Phonolinepreamp ( maybe more critical that what we think ) where the cartridge signal must pass through.
I don't know which were/are the Phono stages-line ones that you use to heard your MC cartridges but I can see due to your comments about that no one made/make the right " honors " to those MC cartridges.
I can see too that you speak about tracking and refer to MC and MM cartridges as well the SG but I don't read anything about your MM cartridges that you own or owned. In reference to tracking I'm with some of the best MM cartridges ...
I heard the SG ( I have to say that with oly 30 hours on use. ) in a very very nice top quality home audio system and my first impression was: WOW!!! but after hearing for some time and after comeback from the initial and nice " surprise " I just don't like what I'm hearing specially on the high frequencies and a little in the un-natural tonal balance of its performance, I'm a little sensitive on both frequency extremes and after a time my ears were " tired " of that SG sound ( maybe because that SG was almost new . ) that was not analog like or music live one it was more like a digital source: a good one digital source ( DVDA ).
Fortunately ( for me ) I asking to change to a normal MC cartridge ( in this case was the Lyra Olympos-Essential phonlinpreamp. ) and even than the Olympos was not perfectly matched to that Phonolinepreamp and that I don't know for sure if the Schroder tonearm was the best tonearm match for it suddenly the " lights " goes ON again: overall no contest.
Next day after heard the Olympos switched very brief to the SG and IMHO was a truly deception.
I always said that the RIAA eq deviation makes a great differences in a MC or MM quality performance and only when you hear cartridges in a phono stage with a RIAA eq deviation lower than 0.1db can you understand how important is that subject.
You have to take in count here that the RIAA eq. is a curve where any frequency deviation build colorations on almost three music octaves and this is IMHO what you was hearing in your MC cartridges through your past phono stages: high RIAA eq deviations, not the cartridge design.
IMHO the SG performance in its today status it can't even the very best MC/MM cartridges when these cartridges are in the right tonearm and with the right Phonolinepreamp, this means in even condition/circumstance than the SG matching set-up.
The SG sounds different? absolutely but IMHO and with all my respect to you and the designer: not better. """
10 years ago I listened the PL first version along its dedicated preamp.
next I posted:
"""
Dear friends: Now I can understand, between other things, why the SG sound quality performance is different, please read the page 13 on this Italian review where you can see that the SG frequency response does not mimic the RIAA eq., there are frequency deviations that " build " those differences that I heard.
We have to remember that what is in the recording follow the RIAA eq. standard and on playback and to be near to the recording the cartridge/phono stage: MC/MM or SG must mimic it, this is not happening with the SG and that's why the differences that we can hear. """
here the first P.Ledermann answer:
""
While I apprecaite all the comments, and empathize with those who love audio and the attempt to explain what they hear though technical terms, there comes a point where it makes sense for the designer to make a stab at clearing the air. I will address two issues: 1) Relevant factual information that might shed some light, and 2) Technical information intended to both enlighten and confound, strictky due to the real world complexity of why things sound as they do.
1) The Italian article did a very good job of explaining to a general audience the difference between "velocity" devices and "displacement" devices, and how RIAA is handled. That was, in part, their objective - it was to inform.
2) Comments that attempt to quantize one's experience by referring to amplitude pertubations are equivalent to four blind men each describing what an elephant is by touching varied parts - and invariably giving an incomplete view of the animal. Sound is complex - yes - if there is a terrible amplitude anomoly, it makes for bad or unlistenable products. But audio has a long litany of products that are quite wonderful that are not "flat".
The human ear lives in the time domain - if this fact is not understood by enthusiasts approaching the field, it is part of audio 101. There are those who insist on .1dB flatness without undertanding that a full sytem tuned and maximized for flatness often introduces phase or time error that are a cure worse than the disease. The small pertubation bumps one sees on a speaker reponse are just that - phase interractions. They give, in part, the tonal flavor of a product.
Although we have made some recent changes on our preamp design to realize a very small change in amplitude and phase flatness, the original product was well received by most listeners and owners. If the frequency response were very bad, that would not have been the case.
What is important to gather (which is hard to do)is what time errors occur in any product, how many, where do they exists in the freq domain, how far do they spread, and how serious are they? This describes only one part of the problem when trying to use technical terms to exlain what we hear. We listen to speakers that are far from flat, in environments that are far from perfect, and often get very good results. Why is that??
The answer in part is that. What is the rise time of the product (how fast is it). Does it ring (resonate) if it is a transducer. How much time shift is there, and how much. THEN, what is the overall response.
If a products design criteria are in accord with certain critical parameters that physics say are good things, it may in fact work well. From then on, your ears are the judge. But do get the laws straight. Amplitude flatness can easily be done at the sacrifice of other MORE IMPORTANT parameters. ""
he followed in a second post:
""
Most manufacturers who have been in this industry for any length of time, as I have for 38 years, know the rules: never say anything publicly, or privately, about anyone else’s product. It is called etiquette, and not shooting yourself in the foot, or a bit higher. One must realize how small this industry is. Attacking products is not only counter-productive as it causes of loss of credibility, but it can misinform those who are trying to learn as well as damage what is left of a tiny industry. You may want to check this with some notables in the industry and not just take my word for it.
To your question. Is the Strain Gauge designed to conform with RIAA – of course it is. Please review my credentials in the industry as engineer at RAM audio, Director of Engineering at Bozak, Senior research engineer at the IBM T.J. Watson research labs, and owners/design of Soundsmith for over 38 years where I have taught and produced many speaker, amplifier, preamplifier, and cartridge products, including now over 40 magnetic cartridge designs.
I am aware that I have “stupid” tattooed on my forehead, an event that happened many years ago in a Galaxy far, far away that I do not care to be reminded about. But why would I go to all the trouble to produce a cartridge and preamp system that doesn’t conform to RIAA? Suicidal maybe???
RIAA conformation. I own and use two Neumann Lathes for a charity project called DirectGrace records. It is intended to rescue children from forms of slavery, including child prostitution, something that occurs as I sure you are aware in large numbers in Mexico City. The Neumann lathes have “adjustments” for RIAA to keep the system tweaked to “conform” as it can and does drift. So do the lacquer masters on which we cut, which change the response. So does the plating and stepped processes to make a stamper, as do the vinyl and pressing parameters used make a record. You may want to speak to real folks like my friend Lincoln Mayorga, who well understands how this arduous process can lead far off RIAA. But I deviate more than .1 dB –
Tone arm interactions can vary RIAA performance quite a bit. So what do you have when you are done?? If you are tweaking for RIAA for .1dB, try tightening the headshell screws and re-measuring. Or maybe mass load the headshell and try again. Or adjust the azimuth, VTF or SRA. You are aiming at a moving target. Are you moving your preamp gun constantly??? It seems it is aimed at me right now.
I have measured the SG in many arms, and recently in my Schroder Reference SG, the new SG design (which you did not hear) it was +/- 1dB from 50 Hz to 12K in conformation with RIAA. And you know what?? I cried when the record was over.
The rest is magic. ""
""
Elsewhere in the article he says:
"We can now state, with an excellent accuracy level, that the natural
frequency response curve of the SOUNDSMITH cartridge is equal to the RIAA curve, this is so
much true that it is not necessary to equalize the output as normally happens with the standard
magnetic cartridge ""
Kirkus that technically is second to none and exparienced gentleman with common sense posted:
""""
But today, we're all trying to get that absolute last "n-th degree" of performance from our turntables and record collections, and we have more high-quality cartridges (both new and old) to choose from than ever . . . so you have guys like Raul that feel the only way to truly hear what a cartridge and tonearm have to offer, is to get the electronics so precise that they're completely out of the picture. I agree with him, and applaud him for his efforts.
BUT we also have a guy like Peter Ledermann, who has developed a strain-gaugecartridge system . . . and this system is AMPLITUDE-sensitive, NOT velocity-sensitive. And this puts the strain-gauge system in a unique position, because it may actually be the first time in over fifty years that there has been serious development in ANY ultra-high-performance, amplitude-sensitive phonograph pickup. And of course, the concept of "absolutely correct RIAA equalisation" is completely non-sequitur to an amplitude-sensitive cartridge . . . and this has ALWAYS been the case . . . we've just all forgotten.
So to the question of, "does the Strain Gauge system feature extremely accurate RIAA compenstion?", the answer is "of course not - that's for magnetic cartridges!". And to the question of "how accurate is the frequency response of the Strain Gaugecartridge/preamplifier combination for RIAA-standard records?", Mr. Ledermann's response is something like "very accurate, when compared to other [conventional] cartridge/preamplifier combinations."
Peter admits the tolerance exceeds +/-1db but refuses to quantify this variance. He seems to prefer simply tell us it doesn't matter. Peter is beyond brilliant, but I just don't get this approach.
I can't speak for Peter, but keep in mind that if a phono CARTRIDGE actually measures +/- 1dB from 50Hz to 14KHz . . . this is quite flat, for any design. While it's true that a properly-designed RIAA phono PREAMP can (and IMO should) itself be better by at least a couple orders of magnitude, once you add the cartridge and measure the two of them together, then the tolerances are entirely different. The Soundsmith straingauge cartridge is sold as a cartridge/preamp system, so if you want to compare it's response flatness with other products, then you have to compare it to other complete cartridge/preamp combinations, not simply to a preamp on its own. """"
PL follows:
"""
The Strain Gauge is a DISPLACEMNET device, not a velocity sensitive device like all magnetic cartridges.
Velocity sensitive devices have a FLAT playback response, so they require RIAA EQ to invert the RIAA recording characteristic used when making masters for record production. RIAA has an interesting evolution; Mr. Galo has written a wonderful explanation of how, and why it evolved and changed over the years:
http://www.smartdev.com/RIAA.htmlDisplacement devices have an INHERENT 6dB/octave curve, very similar to the RIAA (not an accident, BYW)....they DO deviate slightly from the RIAA at two points, BUT, we do NOT correct for this, for doing so would ruin the beauty and simplicity of the device; the one super clean gain stage between you and the music we designed is almost one too many. More than one (to "fix" small anomalies) would be death to the magic ""
unfortunatelly that link disappeared. Never mind.
following for this
@atmasphere post:
"
Hi Peter, the RIAA curve is flat from 318 uS to 3180uS. So there are about 4 octaves that will be spectrally incorrect. That is a lot bigger error than any room I've tested. BTW I've run plenty of room curves over the years- especially at shows. I agree that you see big variations, but not like this (at least not so far anyway).
I've also produced a variety of LPs over the years and I've found that only 1 db variations in the test pressing can be audible (this is easy to hear over a frequency spectrum as opposed to a single frequency, BTW).
So- do you offer an equalizer? "
P.L answer:
"""
Thank you for your comments: they are greatly appreciated.
The subject of human response to amplitude and phase is an interesting one; the standpoint often determines the course of design choices for those of us in the audio design and manufacturing field. I, for one, strongly believe that the human ear is much more forgiving in the amplitude domain than it is in the time domain. After all, many amplitude deviations are the direct result of phase interaction due to resonance, both summation and cancellation, making "amplitude" perturbations audible and potentially objectionable in speaker drivers and cartridge/tone arm systems.
From that standpoint, the cutter heads models also vary considerably; many require one or more frequencies to be fed back with control of both amplitude and phase to stabilize the cutter head. The phase shifts introduced by the RIAA recording curve are further modified by the varied individual characteristics of the equipment used to cut the master. So, where does that leave us? The Strain Gauge is without much phase shift at all. If one leaves out the phase shifts normally introduced by use of a playback RIAA curve, is one better or worse off??
Please also refer to the graph near the top of Mr. Galo’s excellent article called Figure 1;
http://www.smartdev.com/RIAA.htmlIt refers to this graph as the “typical” RIAA response; in reality, it is far from the “ideal” response that one gets from the theoretical filters due to interaction of those filters. This, not the “ideal”, is what we have all been listening to for years with magnetic cartridges! Superimpose a 6dB/octave curve (Strain Gauge) and you will find that it deviates less than plus or minus one dB.
My experience is that severe phase perturbations over a narrow region are very audible, while those that are spread out are much less objectionable. It may well be that this is one of the positive differences one experiences when listening to the Strain Gauge. That, in combination with the general standpoint of multiple stages being inferior to a single stage, makes one think that possibly that too, is a motive for using a "simplified" strain gauge system. There are also numerous other contributors to good sound - extremely low stylus jitter being one.
Although some Strain Gauge preamps in the past have been made to more closely follow the RIAA, some were not. As far as I am concerned it is an open issue that will be addressed from varied standpoints, some of which I have mentioned above. My consideration in the Soundsmith Preamp is to make it mostly flat; the decision to mainly use the inherent 6dB curve of the Strain Gauge elements is based on 35 years of listening and talking with other designers and SG owners. It also provides a standard from which one is not precluded from adding what they believe to be proper EQ to our system, or Soundsmith offering such in the future to those who want it and do not feel that it detracts from the listenability. ""
@atmasphere posted next:
"
So no EQ unit then. If you refer to Stanley Lipshitz's paper, presented to the AES back in the late 70's (arguably the definitive paper on RIAA equalization), it is possible to design an EQ network that will follow the mandated curve correctly, easily better than 1/2 db. He presented very easy formulae to work out practical and accurate values.
It seems that at the upper end of the 'flat area' of the RIAA curve (318uS), that a simple 6db/octave EQ will be off by nearly 24db. "
no eq. that was the version I listened at Boise vetterone home place.
Pl. final post:
"""
I am also concerned that your figure of 24dB is very far off from the reality of the device; it would make it unlistenable! Please observe the "real" RIAA curve in Galo's figure 1, and superimpose a 6dB/octave line on this "real" world RIAA graph, referencing both at 1Khz. The greatly simplified result is that in the response below 1KHz, the SG would be slightly boosted, and above 1K, slightly attenuated. For a cartridge with 70Khz bandwidth and immediate speed of the Strain Gauge, this slight upper end attenuation is not missed at all as there is a definitive acoustic signature that many notice, which more than makes up for this slight "loss".
Noise issues:
When you say, "....allure to the idea of a cartridge that can put out a volt or two." are your referring to the Strain Gauge? If so, that would be an incorrect attribute for the Strain gauge. While ceramic cartridges (displacement devices as well) DO output high voltage, they are also high source impedance devices. The Strain gauge is absolutely neither of those, although I run into many who do think it is. The source impedance is a fairly low, purely resistive 1000 Ohms, and the current supplied is 4 milliamps. The amount that the element varies is less than .1%; this means that the change in voltage is in the range of 3 - 4 millivolts, requiring a gain in the high thirties.
Noise?? In fact, the RIAA EQ inherently reduces high frequency noise and distortion in "normal" preamp circuitry; making RIAA a Dolby of sorts. The absolute requirement for a fairly flat (EQ or not) preamp for the Strain gauge was a bit more problematic 35 years ago, as we had to create low noise circuitry for this "flat" preamp to avoid excessive noise compared with a standard RIAA preamp! Creating a circuit in this day and age with "ultra low noise and immeasurable distortion" is a joy, and very do-able. I would rather listen to this one gain stage and an ultra fast cartridge than anything else """
We have to read all the whole " history " that 10 years ago explain the ram tubes " black thread ".
Unfortunatelly for me in those old times I was not willing to learn not from P.L and not from Kirkus. My mistake, big one.
Rgerads and enjoy the MUSIC NOT DISTORTIONS,
R.
"
