I have just set up the voice server - Mumble
All that you have to do is download it here :

Mumble for Windows

Mumble for OSX

Install it, then just click this link

Connect to Mumble
Copy this link to your browser: mumble://mumble-2.verygames.net:50110/?version=1.2.0
And you are inside

After you already connected to server, go to :

Server >> Connect >> Add New

just give it some name you will recognize and it will be added to your favorites, so you wont need to click on the connection link everytime.