Hi, @baffled2023
Is there a reason you need EXACTLY 15.0Vdc?
14.9Vdc is well within most equipment specifications.
Have you measured the ripple on the output, no load and loaded?
What was the original chip part number, have you looked at its specs?
Are you over thinking the problem?
0.1V in 15V is 0.1 /15 * 100 = 0.66%
Tom.... 
