interesting avatar. Those tubes look like they're in jail.
by the way, 4 ohms loads with Aegir in monoblock mode not recommended (can trip the protection circuits if cranked)
No problems with Aegir monoblocks with my 4 ohms speakers.. even very loud. (Elac Vela BS 403) sensitivity is 86 - which is low, but not super low.
I didn't try with a single block, but my gut says that wouldn't have worked out well. (also, damn the Aegirs get hot. Now with fans on them they only cool to the Vidar levels of heat.)