RIAA Preamp Build (part 5): Extras

Now lets take the basic RIAA (Flat Xover),
and form two more of the most popular EQs:

(D)  The NARTB Standard:  (Artist, Capitol, M.G.M., and many other American pressings) = (C) The 500 Hz Flat Xover + a cap:

and finally,

(E)  The Columbia Microgroove:  (NARTB + a resistor):

We can also squeeze out the RCA Victor 78 rpm EQ from a basic RIAA (flat 500), by adding an additional L-network, but after this we have to start from scratch to punch out the last two, (Decca FFRR, and Columbia 78 std.), because they require more extensive changes.

Well, it shouldn't take much imagination to wire up a switch or two to eek out at least 5 RIAA EQ settings.