LobalWarming
1000+ Head-Fier
Sorry about the troubles... CV4079s are delightful tubes. Can get stiff sockets to 'relax' their death grip with years of rolling.Yeah I tried both sockets with both tubes, equally stiff. There's no way I can get the other tube out without breaking it without tools. It's super stiff. The pins on both tubes were in perfect condition too, so something is up with the sockets I think.
Or... if you're in a rush... can use a small flat blade screwdriver to open up each socket a little. On close examination may notice a too closed or offset socket pin.
Or if you have a spare B9A noval adapter can use that to wear-in the 4079 adapter, by inserting/removing a few hundred times.
As you discovered, it's called tube rolling for a reason. Rolling (side-to-side) the tube into the socket is better than attempting to push straight into the socket.
Could also contact @Deyan about a custom CV4079 adapter.