A 1k resistor represents about 4nV/rt Hz of noise density. So for an MC of 10R (a typical order of magnitude), the intrinsic input noise will drop to 0.4nV/rt Hz. That's the equivalent input noise of a perfect preamp.
Do you have spectra of a silent groove in one of these masters playing versus just the cartridge off the disc? That would be good evidence and technically interesting.
I don't. But its easy to hear the difference: when playing the laquer the surface noise is inaudible, so the noise of the playback electronics is all you hear until the music starts. That isn't the case with LPs, although as I mentioned before the projects we did with QRP were fantastic in how quiet they were- they had a lot in common with the lacquers.
To say the media is great but the playback sucks is accurate but it doesn't matter, the playback is what you get and so no matter how great the media can be in it's quiescent pressed form that's not really the argument. The argument is what performance we get at our ears from LP's, not as it sits in it's sleeve on the shelf. Talking about the latter is moot to the discussion.
To be clear, what I said was the limitations of LP seem to mostly be caused by the playback apparatus. I gave some solutions too: use a strain gauge cartridge; failing that use a phono section that isn't perturbed by RFI at its input (if using LOMC cartridge, such a phono section will not sound any different if a 'cartridge loading' resistor is used). Also proper setup at which most people fail.
I am having much difficulties agreeing with this statement... beyond the chicken/egg dilemma it poses.
I am more inclined to think that the media is flawed; while the playback 'system' is trying to compensate for the many physical limitations of the media.
Would you be able to explain your statement in respect to the following LP media deficiencies issues?
Longevity/Wear? RIAA curves? ChannelSeparation? Inner/Outer groove sonic differences? Lower Octave space limitations?
Longevity/wear is a function of care in playback and how well the cartridge tracks. If the arm is unable to properly track the cartridge the LP might be damaged in only a few plays. But if the cartridge is competently tracking, the LP can last for many years.
Cutter heads are matched at the factory to their electronics and custom equalized on that account. Then the RIAA pre-emphasis is applied. Errors in the RIAA curve are thus in the phono preamp section and this has been well documented over the past 50 years or so. If you obtain an inverse RIAA network for testing this is insanely easy to document!
The cutter employs feedback windings in tandem with a 30dB feedback amplifier; IOW it has 30dB of feedback at all frequencies. This is done to control resonance in the cutter and
also to insure channel separation. Its quite effective! If recording on one channel only, when viewing the groove through the microscope you can see that one side of the groove is perfectly smooth. You might wonder how it could be possible to measure cartridge channel separation, if you think this one through you will see its not chicken and egg at all.
Since the introduction of variable groove spacing, the limitations of the inner grooves really isn't a thing any more than it is for tape near the end of the reel. What
is a thing is that a lot of radial tracking arms are compromised in their ability to track the inner grooves (mostly due to
poor setup of the cartridge in the arm). The cutter head
doesn't change how it cuts the groove when it gets near the end of the LP! The same information that is possible in the outer grooves is also possible and present in the inner grooves with
no loss of bandwidth. This is one of those annoying mythological tropes steeped for decades that simply needs to die. You just need a better tonearm to extract inner groove information. Its a garbage in garbage out thing. Use junk, expect junky results. The lower octave is limited by the cartridge/arm mechanical resonance as I mentioned earlier. The cutter head and its electronics have bandwidth below this limit (IOW below 7 Hz).
You can see that these are all playback issues- they don't exist on the record side.
Like any digital, the LP is limited in what it can manifest by the playback apparatus. We should not see measurable differences between DACs but we do and its no surprise that we hear differences with them too. IMO/IME there is a prejudice thing that comes from a lack of understanding how the LP process actually works. As I mentioned earlier a lot of my mythological notions (a lot of which I've seen expressed in this thread) died a horrible death after I started running the lathe.
Again, not saying the LP is better. I am saying its not nearly as bad as its been made out to be on this thread. One thing I've been wanting to do for a while is to use a class D amplifier with the cutter. A self oscillating class D amp would be inherently more stable in the system and also even lower distortion.
