Dear friends: Yesterday I mounted the Talisman LOMC cartridge that's an extraordinary performer and I did exaustive tests " plñaying " with load impedance and capacitance and no matters what and even that my system has very high resolution with every kind of distortions at minimum I can't detect/be aware of no single anomaly in the HF range and I put focus on that HF range. Nothing.
So with LOMC cartridges current or voltage phono stages designs makes no diference in that loading subject where that " limit trace " does not exist.
So and due that over 95% of the phono stages are voltage designs the important issue down there is the overall quality levels of the design and the quality levels of the excecution of that finished design on the market.
Btw, no one of the LOMC cartridges that I tested performs in a superior way when loaded at 47k, always inferior quality levels against lower loading values. My MM/MI I " historically " load it at 100K.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R. |
I'd imagine
the compliance change may not be big in the manufacturer specified load
range so no one cares. Plus load optimization is usually done by ear
anyway. There is something called the 'Grado dance' that has to do with the low output Grado in the Graham 2.2. I've experienced it myself. In a nutshell, the two are incompatible due to the mechanical resonance frequency. However, the Grado low output cartridges behave in a similar manner to LOMC cartridges and by loading the Grado the 'dance' can be eliminated.
@rauliruegas I recommend that you contact Jonathan Carr and he will confirm our conversation in Munich. It was certainly not my imagination. Again, I have not specified at what frequency the cartridge will be less reactive to the groove. I've been careful about that! Cartridges cover a wide range of inductance values and outputs; what I **have** noticed is that all modern cartridges have bandwidth that exceeds many of the cutter heads that cut the LPs. Our cutter is bandwidth limited by the mastering electronics to go flat at 42KHz (IOW a single pole rolloff is introduced at 42KHz at the output of the mastering amplifiers). A Grado Gold running in a older Technics SL1200 has no problem playing back the output of the mastering system at any frequency it can make from 20KHz right up to the 42KHz cutoff. I've not attempted any frequency above that as the risk of damaging the cutter head is great due to the RIAA pre-emphasis.
Since LOMC cartridges can go much higher than MM cartridges (see http://www.hagtech.com/loading.html) and since I've yet to see loading affect any LOMC cartridge at audio frequencies (although I've only sampled a very few) it is logical to conclude that with my sample set that loading is affecting them outside the audio band due to the mechanical damping caused by electrical loading. I have made this clear in prior posts. That this occurs is not a matter of debate. Since I have not studied all MC cartridges made, its logical and safe to assume that some of them may well be affected at lower frequencies than those in my sample set.
Aristophanes
, a well-known Greek philosopher, once said “Youth ages, immaturity is outgrown, ignorance can be educated, and drunkenness sobered, but stupid lasts forever.” So what's it going to be? Choosing to be ignorant by refusing to study the topic??
@lewm About 20 years ago I conducted a study of loading on phono cartridges in an effort to see if I could make a box that would tell you what the ideal loading of a LOMC cartridge actually was. It was in that study that I realized the loading was not affecting the electrical aspects of the cartridge at all. With many inductors (like an audio transformer) you can 'ring' the inductor with a square wave and observe the results on an oscilloscope. You can then adjust the load on the inductor so there is no overshoot but also not any rounding of the square wave. This isn't really possible so I usually go for a slight bit of overshoot.
What I noticed with the LOMC cartridges in this situation was the output waveform looked like the input squarewave. No ringing, no rounding. All the loading was doing was decreasing the output, especially below a certain minimum load resistance. At this point I realized that this was confirming my prior experience that loading was affecting the preamp's reaction to RFI rather than anything to do with the cartridge. This would also explain how a cartridge can be part of the resistive ratio that determines the gain of an opamp, as seen in current amplifier phono sections, without noticeably affecting bandwidth.
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Dear @lewm and friends : This was the main subject in the first intactaudio post:
"" article in IAR #5 by Peter Moncrief titled "Audio Fallacies Exposed Low Impedance Loads for MC Cartridges" about loading and he proposes that loading down a cartridge helps it keep better contact with the grove. ""
Years ago too Palmer posted in Agon as an answer to atmasphere:
"""
not on tracking which is demonstrably false based on IM tests on tracking performance that I have incidentally performed as a function of load. """
@atmasphere thank's for your comments and I and maybe some one else would like to know which is that "
in my sample set ".
R.
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Dear @lewm : """
I would posit that subjective testing based only on listening is fraught with error, not the least of which is error due to listener bias..""""
do you already made the tests I did it? no? then just do it and you will know that that " listener bias " just does not exist because what you are looking for is if you can detect " anomalies " ( other than little changes due to differences on SPLs due to the load resistor. ) in the specific HF range.
Those kind of listening tests is a good approach to confirm that at least by our ears/brain there is no limit trace problem with the cartridge tracking abilities.
Taske your time and try it or not, is up to you.
R.
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@noromance
great explanation of cartridge loading BTW - I wish someone explained that to me many moons ago - before I read around and figured it out |
