There is no firmware information available for the 851A as the current version is the original. April 03, 2024 10:24 Related articles Why do I have to turn the volume control on my 851A up past halfway to get the volume level I want. Is this normal? Azur 851A User Manual What is the latest firmware version for the 851N? What’s the best way to connect my 851N to my 851A? Azur 751BD User Manual, IR Codes & Technical Specifications