If you’re simply asking which next component to change, then it’s the amp.
BUT, it sounds like you want to change both speakers and amps soon, so I suggest demoing speakers maybe 3-10k range, then get matching electronics.
Should speakers be upgraded before preamp and amplifiers?
On a two year plan to upgrade my system. Wanting opinions on what to do first, looking to spend $10-15k, listening room 14x 30 x 8. Currently have Von Schweikert VR-2 speakers Sansui 9090db receiver Pioneer PL-a35 turntable. Would like to try a system with tube preamp. Thanks