Depending on what inputs are on the back of your sub,you could use Y connectors from your pre out or run bare wire from the amp's binding posts to the sub's binding posts.A sub output isn't necessary.There are many diagrams and videos that explain the various methods on the web:)
Best 25-50 tube amp w/ sub woofer input for sound $2,000
Hello. Looking to upgrade my present tube amp. I have sub woofer which I would like to integrate with a tube amp. Cost around $2,000 used with between 25-50 watts. Must connect to Linn Sonedeck LP 12, Naim CD w/ DAC and 85db Fritz carbon 7 MK II speakers. Thank you.