Removal of volume button if volume control is disabled settings

[roppp]

I see, thanks for your reply.

it can be mightily frustrating to see a control, click on it, only to be rewarded with a "sorry, you can't do that now" message.

That describes my point of view well... Almost half of the UI elements just tell me they cannot be used. 

Imagine knowing some feature "was there a minute ago" but now it's gone.

"volume control->none" as well as "Bitperfect->active" setting is not default setting. So when I intentionally do this setting, I might be not surprised when some UI elements are gone afterwards. 

I understand there can be different opinions about this, but I prefer minimalistic UI