RIP
spanishbuddha Either it's NU1X only problem, or there's another parameter to be factored in, or the instruments you tried are (batch) defective or ….?
porco_rosso Or it could be a batch defect. But I'm not sure about this. The NU1X at JustMusic seems much older and the action felt more worn down. It is definitely there since at least last year.
I have the NU1 too, but as I said I did not install the anti-loud-note firmware, so I can't test it, but I can speculate.
As @porco_rosso and @vagfilm discussed and eventually agreed, there is no way that this is related with the mechanics. This must be software. Since it is not happening on @spanishbuddha instrument and (weaker argument, I know) it is not discussed anywhere but this thread in this forum, I speculate that it's something relatively new in the last iteration of the firmware. Do we know for sure the version of the firmware that's installed? Do we know when was it released? Can you find someone someone else with and older version of the firmware to look at the checksum and see if Yamaha has changed the content without changing the version number?
Wait, on this latter point I can help 😁 I have a zip file of the firmware which I downloaded on May 21st (2019) and the corresponding PRG that's inside shows an April 10 of the same year. Here are the MD5 checksums:
f212c34948b2aadff389448ffce21a87 firmware/NU1x_firmware/nu1x_v210.zip
6ff06fc16ff4f387e98e48f473e3809a firmware/NU1x_firmware/NU1XSETUP.PRG
The vendor firmware page has been updated before November 2020, according to the internet archive's records: https://web.archive.org/web/2020\*/https://usa.yamaha.com/support/updates/nu1x_firm.html
The internet archive sadly does not have the firmware binary cached (because you need to accept terms and conditions to download it), however the version "live" on Yamaha's website is identical to mine. Same story with Europe's version of Yamaha's website. Sleuthing a bit in the internet archived versions of the USA's version of the website, one reaches a roadblock: the oldest mention of the NU1x has been archived in Sept 2017 but the more details about the instrument was cached on in August 2018 and most relevant for this discussion the firmware page was not cached at all ☹️ until few minutes ago when I nudged such caching. I did not check the Europe's website, leaving that fun to you, let alone the Japanese one which might be the best shot.
