Who are using vinyl as main source?

[f1eng]

... Riaa 1976 (I prefer the 1953 but my current Jelco arm will resonate due to the unfiltered set up of the 1953 ie 1953 goes under 20 Hz).

/Mike

Hi Mike, I am intrigued to know what you prefer about the 1953 curve?
AFAIK they are identical apart from the rumble cutoff and with a digital RIAA correction there is not even a risk of the extra phase shift due to the low filter.
No record player is capable of reproducing non-spurious output below ~ 2x Fn of the arm/cartridge so it is not as if you can be missing any genuine musical information below 20Hz.
cheers,
Frank

I hadn't realised there had been so much controversy about this but there's an interesting article in Stereophile which explains LP equalization in some detail here.

Apparently, the low frequency roll-off introduced by the 1976 revision actually starts above 20 Hz (its actually -3.0dB at 20 Hz, -1 dB at 40 Hz) and low frequency tonearm/cartridge resonance is not well-suppressed anyway because the roll-off is too gradual.

EDIT: The high pass filter apparently also introduces low frequency phase errors.

Whether the differences between the 1953 and 1976 curves are audible I don't know but I guess they could be. In a perfect system perhaps the 1953 curve would sound better but I heard a demo of an Orbe/Devialet/SF Guarneri system in which the drive units flapped visibly all the time and someone who had heard a v similar system before said he couldn't understand why it sounded so "flat". It later turned out that RIAA curve used was the 1953 one. Presumably the performance of a drive unit must be negatively impacted if its having to cope with large, low-frequency, warp-induced movements?

I was a noise and vibration engineer working on the design of record players in the mid 70s before going motor racing full time so I am pretty familiar with all this, and sadly there is a lot of mis-information on the net about most aspects of record players from those who have discovered them since they returned to popularity.
The pickup is a seismic type of transducer, and all output from the cartridge at frequencies below about 2x the arm cartridge resonance are spurious. There can be a huge signal at the arm/cartridge resonance, since that is what is happening. It is best removed since it will move the loudspeaker cones away from their most linear range. The exact frequency at which the cartridge output is an accurate transduction of what is on the LP and the magnification at resonance are both dependant on the damping. More damping in the cartridge reduces the resonance peak but raises the lowest frequency at which accurate bass is produced. Damping in the arm is better but doesn't suit all cartridges.
The phase shift due to the high pass filter in the 1976 curve will be considerably less than the bass phase inaccuracy of most (non-SAMed ) speakers anyway, and with the digital RIAA correction in the Devialet there is no phase shift.

I shouldn't worry about -1dB at 40Hz either room effects will be massively more than this. The main thing is a substantial reduction at around 10 to 12Hz to stop the resonance getting to the speakers.

It is certainly true that some people like the 1953 curve more, but IMHO they just like more bass, and the fact that most of it is subsonic grunge doesn't seem to upset the "more bass is better" feeling.

Edit. The LP replay system is not capable of accurately reproducing the bass of an Organ. It can give an indication but not accuracy. OTOH the bass boost due to the arm/cartridge still being influenced by its resonance may be impressive even though not accurate.
In fact quite a few of the LP system "shortcomings" are enjoyed by many since most of them (but not all) are euphonic.