1. If you are A/B’ing with the original board, give the original board at least an hour to come into song. Based on what I’m hearing, I recommend a minimum of 3 hours with 5 hours being ideal.
In other words, if you are planning a quick A/B you will not hear the original board at it’s best. I have 7+ hours of play time on the original board, as of now...if I notice any additional improvements, I’ll post accordingly.
Please note: my original board was "out" for 3 days. I can’t speak to times, if your original board is out longer.
2. I have not swapped in the new board, NOR is mine fully run in...therefore, I can not advise on the hours required for it to come on ’song’ once it is fully broken in, dependant on time "out" of system of course.
3. When you swap in the original board, make sure it is fully ’seated.’ When I removed my original board (to swap in the new board), I noticed there was very light "play" in the ’seating.’
Listening to the original board, completely / fully seated, has been a revelation. : )
[Note: as of this point in time I am only using USB in, NOS setting for my comparisons]