Stewart Pinkerton wrote:

So far as I can tell, only from the mid-'90s did we have DAC chips
which were better than 18-bit linear, combined with low-jitter clocks
and good power supply regulation,

One of the first was my Denon - um - circa 1990. 20bit, good power
supply, and overall a sweet design at the time.

I think 13 1/2 years is close enough to the claimed 15.