I have two Yamaha receivers, an RX-V681 and a TSR700. Using the native app, or the remote control, volume is set in dB, as opposed to an arbitrary integer scale.
Depending on the specific receiver and zone, the max volume varies. For example, on the 681, zone 1 has a max volume of +16.5dB, and zone 2 has a max volume of +10dB.
However, using HA’s media_player control, the highest I am able to adjust the volume to is 0dB, when the volume slider is at 100.
I have checked the states using the dev tools, and HA sees the volume being reported as 1 when the receiver is at or above 0dB. Below 0dB, HA sees some float between 0 and 1 - and volume adjustments in this range work perfectly.
Has anyone solved or overcome this issue? Some of the speakers I’m controlling from this are outdoor speakers, and it would be nice to drive them a little more - especially since some of my audio sources are quieter than others (Chromecast to RCA inputs, for example, is much more quiet than an FM radio source).