We are currently using our Amazon Echo Dot with our Bose Sounddock Series II. It is connected via a 3.5mm AUX cable. Works fine with one wrinkle: If the system has not been used in awhile (e.g. overnight, for a few hours, etc.), the volume will be very low and certainly not at the same level as when we last used it. We usually have to crank up the volume to hear Alexa or what she is playing.
Another option here is to use a Bluetooth adapter for the bose and connect it to the Echo Dot wirelessly. We have such an adapter and we know the start up volume doesn't seem to be an issue (good). The issue we run into with the adapter is we need to constantly unplug/plug the BT adapter and/or unplug/plug in the Bose to get the BT connected. Like the volume, is seems that BT connectivity is also lost after a period of inactivity.
I understand the Bose systems have an auto-off feature, which can be disabled on some models. Is there some way to disable auto-off on the Sounddock Series II? Any other ideas on what is happening would be very much appreciated! Thank you.