Please note that we discontinued the A upgrade service for the following Denon products in December 2015 after 7 years.
AVR-3808 Upgrade to add Audyssey Dynamic EQ, Dynamic Volume and CEC
AVR-4308 Upgrade to add Audyssey Dynamic EQ, Dynamic Volume and CEC
AVC-A1HD Upgrade to add Dynamic Volume and Denon Link 4th
AVP-A1HD Upgrade to add Dynamic Volume and Denon Link 4th
Therefore, these units cannot be upgraded any longer to the respective A versions.