And yes RIAA EQ is not necessary. As I said there were many recording standards which did pretty much the same thing. It just makes good sense to agree on a standard and use it for compatibility.
Records from the time of acoustic 78s to the latest Lps are, for most of the useful frequency range, constant amplitude. If you are using an amplitude responding pickup such as crystal, ceramic, Philco beam of light, Weathers FM capacitance, or strain gauge you do not need playback EQ. The points of inflection at 500 Hz and 2120 Hz will not be addressed but the results are acceptable.
H. callahan wrote: ↑10 Aug 2019 07:21So your theory is that electrical recording heads had to be equalized to make records sound ok on acoustic machines. And what happened when electrical playback became common? Did they stop to EQ and went back to constant velocity?Coffee Phil wrote: ↑09 Aug 2019 20:01Hi Bob,
Thank You! What you linked does state that acoustic records are largely constant amplitude cut. My experience with acoustic records and my phono stage which with other playback curves can provide constant velocity or constant amplitude leads me to agree with that.
There is literature out there which says constant velocity so this has led to discussion (arguement). The fact that early electrical cutting heads were constant velocity and had to be equalized to make electrical records sound correct on machines which had been happily playing the old acoustic records also supports those of us in the constant amplitude camp for acoustic records.
According to your theory all the RIAA stuff wasn´t necessary on electrical playback.