I’ve been playing with Ubuntu Mate 14.04 for a month or so now, The laptop I’ve been testing it on has a scroll wheel on the side for volume so I didn’t notice until now that you can’t put the curser on the volume icon and adjust the volume with the mouse scroll wheel like you can in other Ubuntu versions.
Just pointing it out and hoping it’s corrected in 16.04
Hi,
I’m using UM 15.10 and the wheel scroll works if you click on the volume icon and keep the mouse centred on it!. 
There's two versions of the volume control:
Indicators
This is the default setting in 14.04, but 14.04's version doesn't seem to support this. 15.10 here definitely does. The only closest way is to click then use the wheel on the slider.
Applets
This is the alternate volume control / network tray icon, also available in 14.04 and works with the wheel. This is the default in newer versions.
First, you'll need to change the panel setting in MATE Tweak to "Ubuntu MATE" (System → Preferences → MATE Tweak)
This will destroy your existing panel layout!
MATE Tweak looks slightly different in newer releases.
If you're using the latest Ubuntu Mate Tweak that's no longer a problem if you want to go back. Just click on the Save Panel Layout button & you can revert back to your setup. 
Thanks all, Didn’t know that, I’ve always been able to just hover and scroll. Guess I’ll have to adapt…lol
What theme is that SantFe?.
The main theme is the Bluebird GTK theme, which I played around with the colors a bit. The ICON theme is Cheser, which I also played around with some of the icons. The Window decoration is based on the RazrFX metacity theme I also fooled around with.
1 Like
Thanks for the reply, so you do a lot of fooling and playing around then?.
First time. There’s still a few bugs to work out, like when I hover
over something, like a link in my browser bookmark toolbar I get a
transparent box instead of a background. 
But you can’t learn stuff
without breaking a few eggs.
1 Like
Hi, it’s possible to have volume applet again on Ubuntu Mate 18.04? Now it’s impossible to mute simply clicking with the scroll whell on the volume icon…
You could replace mate-volume control applet with the pnmixer.
sudo apt install pnmixer -y
In the Startup Aplications find the Volume Control
and replace mate-volume-control-applet command with pnmixer.
Log out and back in and you’ll see that the icon changed.
Right click on the tray icon -> Prevferences -> Behaviour tab
In the Volume Control Command text box type in
mate-volume-control
Go to View tab and select the slider orientation. In the same tab you can set the volume meter and volume meter color. Offset 1000 %. If I enable “Use System Theme” icon is buggy for me.
You can set the hotkeys in the Hotkeys tab and in the Notification tab you can enable notifications.
What pnmixer doesn’t show is decibels in the tooltips, but the middle click mutes volume and mouse scroll changes volume.
1 Like