Deryk Barker wrote in response to Kevin Sutton, in part:

>All record playing equipment I've ever encountered had the RIAA curve
>parameters built in....

Some older LPs and most 78s (?) are not RIAA equalized, but use other
curves.  One advantage of some of the older higher end preamplifiers (tube
types) like the Fisher 400CX was that there were other equalization choices
possible, one being an old Columbia curve.  I just sold my ancient Fisher
alas.  It also had a derived center channel with independent control.

Jim Hunsley