Do you feel that the sound from the speakers is thin? Especially at moderate volume? If your sound is lacking weight, then an amp upgrade would make sense. But this sill be very obvious.
Those are very good speakers. You can change them but you risk upsetting the dynamics of the system and creating a cascade of issues.
It sounds like you don't have any line conditioning in place and that is probably something worth looking at. Furman makes nice products. I think for the money, Puritan might be the best on the market. A PSM 136 is not crazy expensive ($1600) and will do a lot to improve sound and comes with a pretty good power cord.
Are you using the stock tubes in the BHK or have your rolled in NOS tubes? That will have a shockingly large impact and be at most ~$250.
Those would be the places I would start.
Those are very good speakers. You can change them but you risk upsetting the dynamics of the system and creating a cascade of issues.
It sounds like you don't have any line conditioning in place and that is probably something worth looking at. Furman makes nice products. I think for the money, Puritan might be the best on the market. A PSM 136 is not crazy expensive ($1600) and will do a lot to improve sound and comes with a pretty good power cord.
Are you using the stock tubes in the BHK or have your rolled in NOS tubes? That will have a shockingly large impact and be at most ~$250.
Those would be the places I would start.