Don, you're probably right when you point out that the reproduction chain in vinyl playback is complex, which means it's difficult to forecast a meaningful SNR number.
Here's a good read on the theoretial DR of vinyl:
https://www.st-andrews.ac.uk/~jcgl/Scots_Guide/iandm/part12/page2.html
The author assumes that the LP disc is made of diamond and makes some calculations to estimate DR.
However, DR and SNR is not exactly the same thing...
When it comes to cartridges, it's been said that the Clearaudio Goldfinger Statement, at the ridiculous price of $15k, has an SNR of more than 100 dB:
http://www.needledoctor.com/Clearaudio-Goldfinger-Statement-Phono-Cartridge
I don't know where those figures come from and how they are measured, but this guy claims the same thing:
http://www.purevinylclub.com/key-advantages/
I know the 2 latest sources are dubious, and cartridge producers don't publish SNR data of their über expensive gear.
In other words, it seems like it may be possible to keep SNR at around 90 dB in vinyl playback, given the LP disc doesn't ruin an otherwise perfect audio chain...
Thanks for the links, very interesting. I remember reading, someplace, ages ago, that the theoretical limit was around 100 dB, but for real (standard) vinyl was closer to 70~80 dB due to the material and manufacturing, and rapidly dropped to 60 dB or so after a few plays due to damage, dust pick-up, and so forth. In practice the best I have measured (again years ago, but with the best TT's of that time) was around 70~75 dB. That first link is sort of mixing up SFDR and SNR but the general trends are there... Surface noise, eccentricity (off-center hole, out of round grooves), warps etc. on the record combine with TT wow and flutter, rumble, electrical and mechanical noise, etc. to reduce real-world SNR into the 60's at least when I have measured it. Of course the source is also a factor; heavily compressed pop music may have much lower dynamic range than the TT system can deliver. Some TT's way back when would automatically center a record, and of course there are endless variations on clamps, mats, vacuum hold-down, and other schemes to get rid of record warp. And cleaners (just read an article describing the virtues of a "mid-level" cleaner suitable for "middle- to high-end audiophiles" that listed for $5,000 USD -- ouch!) Long way from my DiscWasher brush and fluid that I used so religiously back then.
I am familiar with the difference between dynamic range, which I call spurious-free dynamic range (SFDR), and SNR. That is why I used dynamic range and not SNR is mentioning DAC specs. To put numbers on it, for a sampled data converter (ADC or DAC), theoretical SNR goes by 6N and SFDR by 9N where N is the number of bits.
The Clearaudio cartridge is one of several claiming exceedingly low distortion. Again, I don't doubt it is possible, just that anything like that is achieved in the real world. That said, I have not kept up with the state of the art in records, so perhaps modern LPs are capable of >70 dB. The best tapes I have measured hit up around 80~85 dB IIRC (1" or 2"masters) and a modern front end should beat that. And for those with ultrasonic hearing a record can contain and cartridge can extract frequency content well above 20 kHz, all the way to around 100 kHz or so. I used to have (actually the store for which I worked owned) a metal measurement LP along with a handful of pristine test LPs manufactured with a special harder material. Wish I had kept a couple...
I remember the change I heard and measured as I stepped up from a cheap BIC TT through Dual and Garrard to more expensive models like Thorens, Linn, Oracle, etc. I own an older TT whose model I've forgotten, a Linn copy, and I put a Magnepan UniPivot on it after trying several other arms (Grace, SME). Reducing mechanical noise and improving speed stability can make an audible improvement, but at some point you are limited by the record itself. My collection took a big step up when MoFi, Telarc, and others started producing good-quality LPs (this was the late 70's and early 80's when standard vinyl was getting thinner, more warped, noisier, and generally poorer IME/IMO). I have heard a few good systems recently and they sound great to me, but not great enough for me to pull my TT out of storage. I've pretty much abandoned it for digital, and the best digital recordings to my ears are better than the best vinyl. The main problem I've had is as Amir and others have said; remastering/editing noisy old tapes by filtering and compressing them and putting them on CD has created a lot of CDs that, while they should be technically superior, sound worse. Blah.
I expect the SP10 will be an excellent TT, at hopefully a reasonable price, whatever that means. I didn't participate in your poll because I simply don't have a good feel for it; I would guess in the $5k to $10k range but given the price of other top-of-the-line models from e.g. Shure I would not be surprised to see it up in the $15k to $20k range or even higher. We'll find out soon, hopefully. Along with test results showing what sort of performance it achieves.
I am surprised there aren't more linear-tracking arms and TTs around these days. I expected all the SOTA systems to have vacuum hold down, diamond bearings, and linear arms these days.
Here's a question for you vinyl gurus that I have thought about from time to time: Has there been research into the RIAA curve, does it need updating to take advantage of modern equipment (recording and playback)?
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