I had issues with the USB port and have to service the M51 because the USB port stopped to work no matter which computer you used. They changed the motherboard and said that it is not common the USB to fail. I am not sure if this have to do with your issue. I had using the USB regen when USB...

Hello, In the previous post you have a link with the firmwares https://mega.nz/#F!K4AkxLoZ!G3zsDcfkLV6zWMXI56KFRg Best regards

Hello, Here you have the NAD M51 firmwares I have available (1.39, 1.41, 1.43, 1.50), the 1.39 is only valid with old M51's with different motherboard, but I think you can flash another version if M51 does not start after 1.39, at least I did this with my M51 (currently I use 1.50 and sounds...

Better send a pm with the email, attached files are not displayed. If someone have the 1.43, I would send a pm with the email. Thanks

I attached 1.39 and 1.41. Is there somewhere with the 1.43?

Email sent to you! Take in mind that only old M51's accept firmware v1.39. Mine does not accept it because is s/n: H48xxxx. Personally I think it sound fantastic with firmware v1.50. Could be a mite that v1.39 sound better in old M51's? I would like to see someone making a side to side...