That resistor will do that from a tremendous electrical fault being present in the amp.
Most all of the leads in your kit that are poking through tube sockets and terminals need to be bent up around the terminals, resoldered, then properly trimmed. I recommend the CHP-170 side cutters to get close to the terminals when trimming the leads.
The wire going into A4/A5 has too much jacket stripped off. If this touches the chassis, it will destroy your power transformer without the fuse blowing.
This build also looks like it was either done with lead-free solder or an iron not turned up all the way, so definitely remedy those issues if at all possible.
