Are you asking abou the tone control characteristics?
I would
opine (and that's all that this is, an opinion based on anecdotal information & memory!) that they're not uncommon, although the range is (or
may be) somewhat more subtle than tone controls of the old days (to wit, the 'seventies). The turnover frequency is on the high side, though, similar to the old days' typical tone controls.
Since I
just happened to look this up yesterday for a tone control question Someplace Else
Here's a pretty typical, slightly high-ish-end tone control scheme for Yamaha's ca. 1978 CR-2020 receiver. This one has two different turnover options: 500 Hz (pretty typical) and 125 Hz (more subtle and 'audiophile', with respect to this component's era). This graph (from the owner manual, and I apologize for the quality of the reproduction) shows the maximum range of the controls -- which is pretty unsubtle.
View attachment 50735
Note that this receiver also has a boost/cut "Presence" (midrange) tone control as well (and for better or for worse).
CR-2020 is on the right in this glamour shot of two
almost-super-receivers from the mid/late 1970s
Semi-monstrous 1970s soiled state receivers by
Mark Hardy, on Flickr
(as befits the stature and maturity of these two
grandes dames, this photograph was taken with 35 mm film
).
Yamaha made up for their fairly ordinary tone controls, to some extent, by offering a variable loudness control in most of their components for quite a few years. The variable loudness was (is), arguably, more useful in the real world. But, again, that's just an opinion, too!