The AVR 151 is built on a platform distinct from the higher-end HK models (like the AVR 3600/3700). Its internal chipset (likely based on a specialized DSP from Cirrus Logic or similar) does not support downloadable codec upgrades (e.g., adding Dolby Atmos or DTS:X via software). The software version installed at the factory is the definitive feature set for the unit's lifespan.
The receiver will scan the USB drive and display the new software version. Confirm the update prompt. The front display panel will show a progress bar or text reading "UPDATING...".
Confirm the prompt to begin. Do not disturb the power grid, press buttons, or disconnect the USB drive while the OSD reads "Flash Writing" or displays a percentage progress bar.
