I'm not a tech one, but listening to the two tracks, the A8 one seems faster. So, if a belt is slow could be the Retro's one.
Or, is it possible A8 has a too fast belt? Haha...
We have techy guys onboard. We might wait their opinion.
Obviously, the answer could be the digital archive file from the company site, but BRJ 18 has not been released yet..