I've installed a Mumble server for voicechat! PM me for the server details to join voicechat.
Most likely, nobody will be online now (Friday night), but I'll hang out there on Sunday.
I know that some forumers use Discord for voicechat. Unfortunately, Discord on Arch Linux still has the bug that breaks voicechat for me -- it's a known problem, but still not fixed. The program is closed-source, all we can do is hope for a bugfix. Mumble, instead, is open-source software, and has better latency than Discord.
-- Simon