Most mechanical things work better when they are warmed up. Cars certainly do. Some tires, need warm-up. What is the problem? Too much effort?
No, they're also good for pulling your Porsche out of the mud it easily gets stuck in.
Until you have some experience with the top MMs, you can't really start pontificating about their inferiority based on high inductance, high DCR designs you tried 30 years ago.
I have had sufficient experience with top MM's and I have not only measured them, but I reasonably understand their theory of operation, conveniently brought forth, decades ago, by Shure engineers in 'Audio' magazine.
For everyone who is not up on all this:
A moving magnet or MM is a phono cartridge with a fixed coil (can be any amount of inductance up to 2H or so) that moves a stylus and its cantilever that contains a magnetic material. Sometimes it is called 'moving iron' for this characteristic in construction.
A moving coil is just the opposite, with a large fixed magnetic structure, and a tiny coil, (Ortofon once used 28 turns) that ultimately moves the stylus.
The MM system is by essential design, a 4 pole rolloff system.
The MC is by essential design a 2 pole rolloff system, and invariably has a wider effective bandwidth, with lower attendant phase shift and faster risetime.
In fact, the USUAL electrical resonance of a MM system is within the 20K limit, and is typically OVERDAMPED, in order to smooth the rising MECHANICAL resonance that starts rising also below the 20K limit and the two resonances are arranged to give the smoothest audio response up to 20KHz or so, and then fall at 24dB/oct.
Just look at the page that I put up recently, and compare a typical MM to a MC in bandwidth, there is a BIG difference. This actually gives a MM cartridge another 'degree of freedom' to adjust the frequency response to compensate for 'scanning' losses as well. The MC doesn't normally have this capability, so SOMETIMES the MM cartridge can be made to have an extremely flat response with a specific test record. This can be done by adjusting the output capacitance to make the best response.
While Shure, and most probably other MM cartridge manufacturers have made serious changes to their MM cartridges, the V15-5 being one of the best, the vast majority of MM cartridges follow the MM Shure M91 model more closely, and suffer from severe risetime limitations caused by the 4 pole rolloff.
It HAS BEEN MEASURED, not just by me, but independent sources as well.
Now, what does this have to do about differences between Scott's opinion and my opinion, on the matter of the sound change between two sides of a test record?
That is the REAL question, which I will get into later.
For everyone who is not up on all this:
A moving magnet or MM is a phono cartridge with a fixed coil (can be any amount of inductance up to 2H or so) that moves a stylus and its cantilever that contains a magnetic material. Sometimes it is called 'moving iron' for this characteristic in construction.
A moving coil is just the opposite, with a large fixed magnetic structure, and a tiny coil, (Ortofon once used 28 turns) that ultimately moves the stylus.
The MM system is by essential design, a 4 pole rolloff system.
The MC is by essential design a 2 pole rolloff system, and invariably has a wider effective bandwidth, with lower attendant phase shift and faster risetime.
In fact, the USUAL electrical resonance of a MM system is within the 20K limit, and is typically OVERDAMPED, in order to smooth the rising MECHANICAL resonance that starts rising also below the 20K limit and the two resonances are arranged to give the smoothest audio response up to 20KHz or so, and then fall at 24dB/oct.
Just look at the page that I put up recently, and compare a typical MM to a MC in bandwidth, there is a BIG difference. This actually gives a MM cartridge another 'degree of freedom' to adjust the frequency response to compensate for 'scanning' losses as well. The MC doesn't normally have this capability, so SOMETIMES the MM cartridge can be made to have an extremely flat response with a specific test record. This can be done by adjusting the output capacitance to make the best response.
While Shure, and most probably other MM cartridge manufacturers have made serious changes to their MM cartridges, the V15-5 being one of the best, the vast majority of MM cartridges follow the MM Shure M91 model more closely, and suffer from severe risetime limitations caused by the 4 pole rolloff.
It HAS BEEN MEASURED, not just by me, but independent sources as well.
Now, what does this have to do about differences between Scott's opinion and my opinion, on the matter of the sound change between two sides of a test record?
That is the REAL question, which I will get into later.
OK, so it's exactly what I said. You only have experience with high L, high R designs from 30 years ago and are generalizing from those particulars. A modern Grado (which I admit I have no experience with) has a coil resistance of 2R and an L of 2mH. The EPC100C mk4 was 30R and 20mH, flat to 80kHz, tip resonance at about 100kHz, better s/n than any MC I'm aware of.
But it does not not resolve enough! That is why Scott can't tell the difference between the two sides of the same recording. This test record was NOT made just for fun, but to show differences.
I don't know myself, you zeroed it on it without asking so I assumed you must know. I've heard his CD rips from it on my old ESLs and they sounded quite good. Listening aside, his cartridge "resolved" well enough that he could easily see waveform differences from one side to the other.
This is the problem, everyone:
Scott decided to evaluate a Wilson Audio test record to hear and measure what he could find. He ultimately mentioned that he heard no difference.
What is then the problem? Fake test record? Poorly resolving phono cartridge and playback system? Tin ears?
I think that the best that I can make of the situation, is a poorly resolving phono cartridge. From some experience, I think that might be the problem.
Now, what do I know about this test record?
Well, at a CES, I passed by the Wilson Audio booth, and I got brought into a conversation with Dave Wilson.
Now I know that Wilson Audio is not highly regarded by many 'critics' here. And even I must say that their speakers, like Porsches, are just too darned expensive.
However, this was the 1980's or so, and in the 1980's I worked on circuitry for Dave Wilson, including a 30 ips master recorder (what the test record sample came from) and advanced all jfet microphone electronics with +/-50V supplies and direct coupled, except for the input, when using certain microphones with phantom powering.
I had also gone to recording appointments with Dave, as an assistant, and heard live vs recorded comparisons with the 30 ips tape recorder and the WATT 1 loudspeakers that I still use today. However, I never worked FOR Dave Wilson permanently at any time.
In any case, Dave took me aside and told me about this test recording that he did, almost by accident, because of the differences they heard when transcribing the output from the 30 ips recorder to other media.
They were so shocked that the difference was as detectable as it was with a professional A/D-D/A converter added, that they decided to make a test record with the pure analog on one side, and the added AD-D/A.
So they had me listen, at the time, with their set-up. They didn't use 'forgiving' speakers like the Met7's, (I have 3 pairs in service at the moment), but WAMM or WATT-PUPPY playback with the best equipment available.
I got a copy, and somewhere along the line, I recommended it to Scott Wurcer. I am sorry that I did, somehow, at the moment.
Scott decided to evaluate a Wilson Audio test record to hear and measure what he could find. He ultimately mentioned that he heard no difference.
What is then the problem? Fake test record? Poorly resolving phono cartridge and playback system? Tin ears?
I think that the best that I can make of the situation, is a poorly resolving phono cartridge. From some experience, I think that might be the problem.
Now, what do I know about this test record?
Well, at a CES, I passed by the Wilson Audio booth, and I got brought into a conversation with Dave Wilson.
Now I know that Wilson Audio is not highly regarded by many 'critics' here. And even I must say that their speakers, like Porsches, are just too darned expensive.
However, this was the 1980's or so, and in the 1980's I worked on circuitry for Dave Wilson, including a 30 ips master recorder (what the test record sample came from) and advanced all jfet microphone electronics with +/-50V supplies and direct coupled, except for the input, when using certain microphones with phantom powering.
I had also gone to recording appointments with Dave, as an assistant, and heard live vs recorded comparisons with the 30 ips tape recorder and the WATT 1 loudspeakers that I still use today. However, I never worked FOR Dave Wilson permanently at any time.
In any case, Dave took me aside and told me about this test recording that he did, almost by accident, because of the differences they heard when transcribing the output from the 30 ips recorder to other media.
They were so shocked that the difference was as detectable as it was with a professional A/D-D/A converter added, that they decided to make a test record with the pure analog on one side, and the added AD-D/A.
So they had me listen, at the time, with their set-up. They didn't use 'forgiving' speakers like the Met7's, (I have 3 pairs in service at the moment), but WAMM or WATT-PUPPY playback with the best equipment available.
I got a copy, and somewhere along the line, I recommended it to Scott Wurcer. I am sorry that I did, somehow, at the moment.
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Now that you made yourself the honour to depart from your previous posts (performance-cars analogy and arrogant/unsupported dropping of all MMs and any MC below $500), you start a peculiar start:
Cartridges are designed to be used as electric generators, not as motors.
Foundamentals are the same, dynamics are not.
Superposition can not be unconditionally applied, as parts of the mechanical section can show non-linear behaviour.
Moving Iron is not the same as moving magnet. There are differences in principles of operation and construction.
I would like to see supporting proof that MMs and MCs have different number of pole roll offs. My understanding is that they have the same number and this number is greater than 4. Some of these have (or they can have) different fc and Q when comparing between MM, MI, MC.
George
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OK, Gapagag: How about 330 milli-Henrys, 250pf, 950+47K load. 17.5KHz or 450pf,720 milli-Henrys,630+47K load? 8.85KHz. Two famous Shure cartridges.
I posed this question before but it was not answered. How can you be so sure that the waveform differences are not due to analog playback differences between two nominally identical tracks on two different sides on an album? I can imagine that the process of cutting two different tracks and playing back those two tracks would introduce more variation than the AD/DA process. Just think about the lousy channel separation of vinyl as one source of error. At any rate, you can't decide what is what on the basis of this test.
This as a separate issue from the audibility kerfuffle that bubbled up.
Well, Vacuphile, they TRIED to show people what they heard in the studio, AND I know that they tried to make both sides as identical as possible.
It may be. I can come up with a dozen possible reasons. Maybe more. That's why I'm highly skeptical of zeroing in on one without really knowing what's going on (not even knowing what the cartridge is!).
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