Tubes and light weight bass


hi everyone

my current system uses shanling sp-80 tube monoblocks, mapletree line 2A tube pre, esound E5 cdp and usher 6371 speakers. I think that bass is on the light side.
I know that when you go with tubes you might lose some bass on the way but i think i lost considerably.
Any suggestions for improvement ? Maybe replace preamp?
Thanks for all comments
icorem
Thanks for all comments so far.
I definately want to keep my tube amps for their overall advantage (to my taste - is it). I will try some of your suggestions and see if there is any improvement.
I will try playing with speaker positioning although my listening room structure is problematic.
Icorem, I own Esound CD-E5 and Dussun V8i int amp and thinking about picking up a pair of Shanling SP-80. Speaker is IRS Sigma (200 lb 3 way with ribbon mid range and tweeters). I bought Usher Be-718 Tiny Dancer on impulse hooked to Usher R1.5 but just sold it. Isn't bass strength of Esound CD-E5? Would you say CD-E5 and SP-80 was good combo for classical music? Thanks in advance.
I owned a pair of Usher 6311 and tested them with various amps : for me they are not an easy load and do not match well with tube amps.
I achieved very good results with Nuforce amps / ModWright pre.