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.
