audioOS 9.9.13.3.1 (build 17D50) is an official Apple over-the-air update for the HomePod, released on 2020-01-28T18:34:07Z. The update package is 946.44 MB. This is a delta (partial) update that requires 12.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: db4876f6cd592b2cfdf97a5f156c9c795c0fd1ea.zip.