Dear @intactaudio : atmasphere posted to you:
"""
first, 47K is the industry input impedance standard for phono preamps. Second, I had a conversation with Jonathan Carr (well known of Lyra fame) on this very topic and it was he who mentioned to me that loading at 100 ohms or the like would have the effect of reducing high frequency performance....""
btqw, the 47k industry standard has no direct relationship with LOMC because 47k was choosed for the MM cartridges before the existence of MC cartridges and even that latter on appeared the MC 47k stays for the owners can use SUTs because does not existed active high gain phono stages.
Now, atmasphere said: " i had a conversation... "" . He talked with no evidence of that conversation that showed that " limit trace " in anyway.
Atmasphere mentioned WBF where JC participated and in that forum JC never mentioned that " limit trace... " that ( for me ) exist only in the atmasphere imagination and as Palmer said is false..
Here are the main JC highligths when he posted down there in the loading subject:
"""
Regarding loading of low-impedance MC cartridges, in general I recommend trying to reduce any capacitances present between cartridge and phono stage input to as little as possible. Use the lowest-capacitance phono cable that seems decent, turn off any additional capacitance in the input stage of the phono amplifier etc.
The reduced capacitance should make it possible for you use a wider range of loading impedances without having the sound go bright, peaky or thin-bodied. Conversely, any excess capacitance between cartridge and phono stage input will almost certainly force you into choosing lower loading impedances to save your ears.
Being able to use higher-value loading impedances should allow you to hear more of the dynamics and resolution that the cartridge is capable of, while using lower-value loading impedances will limit how much of the cartridge's dynamics and resolution that you can usefully extract.
As you said, live music is energy, and audio reproduction equipment should suppress that energy to the least extent possible.
hth, jonathan """
normally cables does not comes with low capacitance ( 32pf as the JC cables. ) but a little high one.
"""
My comments are based on an objective understanding (measurements, calculations, and simulations) of what a low-impedance cartridge generator is, what an interconnect is, what happens when the two are combined, what happens when resistors of various values are added to the mix, and what happens when extra capacitance is added. A low-impedance cartridge has an inductive generator, while a phono cable has significant capacitance. Put the two together and you get a huge spike at ultrasonic frequencies. These frequencies are much too high for any human to hear directly, but fall in a band that is likely to impair the linearity of the phono stage in much the same manner as excessive RF. When we "load down the cartridge", for the most part we don't affect what the cartridge does at all (unless the value of the load approaches or drops below the internal impedance of the cartridge). What adding resistive loading at the phono stage input accomplishes is to dampen the resonant energy of the ultrasonic spike, and give the phono stage an operating environment isn't so likely to trigger any latent non-linearity tendencies that the phono stage circuitry may have.
For the reasons given, the phrase "cartridge load" is misleading. "Phono stage input terminator" is a better description of what really happens.
Increased capacitance between cartridge and phono amplification circuitry will lower the frequency of the ultrasonic spike, which requires the application of lower resistive values to dampen the spike. Reduced capacitance between cartridge and phono amplification circuitry will increase the frequency of the ultrasonic spike, which can be tamed with higher-value resistive values. """
some one there tell JC the first statement here and followed by JC answer:
"""
you are not really affecting the audible high frequencies with any resistive load shown.
JC:
Not directly, no. To claim that the loading affects the measurable frequency response of the cartridge is bogus. However, if inappropriate loading bathes the phono stage in copius amounts of high-frequency noise, it may start to distort (unless the designer implemented various techniques to make sure that this won't happen), and the result will likely be intermodulation distortion. IMD products can go low enough to fall within the audible band (even when the stimuli are ultrasonic), and IMD nearly always is not harmonically related to the signal, making it particularly grating to the ear. ""
JC followed wiith this on his cartridges:
""" When authoring the documentation for our post-2009 cartridges, I went up as high as 600pF cable capacitance (to cover audiophiles who may keep their turntable in a separate room / closet). The official loading recommendations for the Delos, Kleos, Atlas, and Etna reflect this wide range of cable capacitances, and the inclusion of highly capacitive cables for special circumstances is why you may see loading values as low as 95 ohms suggested in our literature. """
"""
jc
Higher capacitance values should be paired with lower resistance values, and vice versa.
The loading resistor value is placed across the phono cartridge's output terminals, which means that any output voltage produced by the cartridge will be forced to flow through the load resistor in the form of current. The higher the load resistor value is, and the farther the net impedance is from the cartridge's internal resistance, the less current will be produced. Conversely, the lower the load resistor value is, and the closer the net impedance is to the cartridge's internal resistance, the more current will be produced. """
This is what a pair of audiophiles posted there:
"""
I have been experimenting lately with resistive loading on my Pass XP-27 phono stage. I am using the stock SME phono cable that came with my 30/12A table. I have an AirTight Supreme cartridge. I am finding that my previous setting of 47K ohms now sounds a bit flat and thin to me. There seems to be a lot of resolution and dynamics but the sound is a bit less natural or real than I am finding with lower settings. I have been gradually lowering the load values (increasing the load) and am now comparing the 500, 350, and 220 ohm settings. I prefer these because they seem to improve the sense of weight, body, tonal richness and warmth of real instruments without seeming to diminish dynamics, liveliness or resolution. In fact, the resolution seems greater. There is also an increased sense of palpable presence and more natural sound.
Nick (Doshi) also pointed out that the added "detail" at the say higher loadings actually obscures "real" information. I hear what he’s talking about with the Atlas and other cartridges
My MSL Platinum signature was best with 250ohm at the time with Magico M3 and pass xp-25. Now with Pass xs i prefer 330ohm.
1k and higher it becomes thin and i hear distortions.
So i think your recent findings are right. """
@intactaudio and friends we can read in those posts that JC never mentioned " limit trace... ".
JC is very knowledge gentleman not only in cartridges that's his speciality but he knows a lot on tonearms, TTs and Phono Stages because he contributed in a very well regarded PS design and build it.
I know him very weel and I know that what he post he posted because he has evidence because he always makes calculations, charts, modeling and the like. He is not a stupid person, is some one I respect a lot even that in the past he and me do not been in agreement in some issues mainly because my amateur knowledge levels.
Btw, here what Ortofon said on the loading issue and that's different to what JC posted:
"""
The lower the load impedance, the higher the current and the more dynamic the sound.
Best regards
XXXXXX
Ortofon A/S
[FONT=&]Playing with the input impedance means also playing with the sound character. The influence of the load impedance on the differences in sound is caused by the change of the crosstalk levels and the amplitude raise at the resonance frequency. The lower the load impedance, the higher the current and the more dynamic the sound.[/FONT] """
So and for me, the " limit trace..." issue is still false till some one can comes here ( as @lewm said: jumps here. ) and proves/shows true evidence and not bla, bla.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
