The Bendix 6094 is the most durable EL84 variant on the planet. Though not a play and play replacement for the EL85 / 6BQ5, with some re-soldering of your EL84 sockets you can have the best built tubes in your amplifier. If you want to push the limits of what you thought an EL84 could do, this is the tube for you. The famous Bendix Red Bank vacuum tube factory made legendary tubes for military and aerospace applications. Their tubes were built to be the very best and were known to last many thousands of hours. These 6094 are not only built well, they sound awesome. Their tone is firm and aggressive with no sign of weakness.
If you don't want to re-solder your socket to use this tube, get the plug and play adapter here.