Might be just a characteristic of tubes to some extent. I have experimented with the following tube vs ss preamps and my results were similar to yours.
Adcom GFP-750 SS Preamp
CJ PV-14L tube preamp
CJ PV-12 tube preamp
Audio Research LS16 tube preamp
Other gear: CJ Premier 11a tube amp. Thiel CS 1.5 speakers. Cary 306/200 CD player.
Adcom: Had the the best frequency range with low, tight, and fast bass and higher treble extension than any of the tube preamps I've compared. Not quite the air, soundstage, or transparency of the tube preamps.
CJ PV-14L: The sweetest sounding of the preamps listed here but seemed to roll off the lows and highs a bit more than I liked in my system. Might be a nice match for a somewhat dry or sterile sounding system.
CJ PV-12: Similar to PV-14L above.
A.R. LS16: Broader frequency response vs CJ, a bit better bass with punch, faster transients, better treble. Not as sweet as CJ. Doesn't sound as "tubie" as CJ. Not quite the low end punch or high frequency extension as the Adcom GFP-750 but still retains some of that tube magic missing in the Adcom.
I mostly use my A.R. LS16 but still own the Adcom GFP-750. For me in my system, A.R. LS16 has the best sound. Best value would go to Adcom GFP-750.
Adcom GFP-750 SS Preamp
CJ PV-14L tube preamp
CJ PV-12 tube preamp
Audio Research LS16 tube preamp
Other gear: CJ Premier 11a tube amp. Thiel CS 1.5 speakers. Cary 306/200 CD player.
Adcom: Had the the best frequency range with low, tight, and fast bass and higher treble extension than any of the tube preamps I've compared. Not quite the air, soundstage, or transparency of the tube preamps.
CJ PV-14L: The sweetest sounding of the preamps listed here but seemed to roll off the lows and highs a bit more than I liked in my system. Might be a nice match for a somewhat dry or sterile sounding system.
CJ PV-12: Similar to PV-14L above.
A.R. LS16: Broader frequency response vs CJ, a bit better bass with punch, faster transients, better treble. Not as sweet as CJ. Doesn't sound as "tubie" as CJ. Not quite the low end punch or high frequency extension as the Adcom GFP-750 but still retains some of that tube magic missing in the Adcom.
I mostly use my A.R. LS16 but still own the Adcom GFP-750. For me in my system, A.R. LS16 has the best sound. Best value would go to Adcom GFP-750.