Is there better amp for bass then Cary Rocket 88

+1 to add a sub (or two). I did perceive somewhat more bass when I swapped tubes in my amp (not Cary), but would agree that, in general, if you want more bass, and if you already have a decent modern amp, change speakers or add a sub. Your bass and mids are likely to improve.

+3 for the sub(s). I have the Cary 808 Rocket 88 R version and do use a sub as well. I'm not sure if it's the amp or my speakers but am very satisfied with the results with the sub. A very nice feature is being able to control the sub volume.

IMO, the Rocket 88 goes very well with classical music; warm and sweet sounding, not great in detail but overall a very good coherent sounding amp top to bottom. What are your sources and preamps? Perhaps you might try different sources or preamps if it's not the speaker. If you're just looking for other tube amps, VTL, ARC, Pathos, Cary V12 as mentioned are some which would likely be a good candidate.

With the 6ohm load, even at 90db, it might be a speaker/amp issue. Your speakers are rated at 30hz. I'm afraid you have three options, add a sub, change speakers, or change amp.

Michael I strongly agree with you. My SS phono stage into my tube pre to tube amps pumps out incredibly rich bass. I would entertain the use of an SS pre myself but I absolutely love the imaging that my modded little AE-3 AES preamp makes. It is magic. But let me emphasize that an SS pre might sole this problem. But keep the tube power amp!