@russ69 from the pictures of the ’98 I’ve seen, I hear you. That line of pre certainly evolved since the SLP 90 & ’94, didn’t it. I still own the SLP 90 that I upgraded from with the 05, & the SLP 90 truly is a "sweet LITTLE preamp" (its power supply must be a quarter of the size of the ’05’s power supply, and the chassis of the preamp section is way smaller by comparison).
But speaking of a "warm preamp", I always thought of my SLP 90 as that. Maybe it wasn’t, maybe it was just the set up it was in, or mabe it was the Mullard 12au7s. I felt it was a huge sonic upgrade from the B&K HT preamp I had in front of my (at the time of upgrade) ARC VTM 120s. It went from being in front of the ARCs to being in front of a Cary V12 (which is still there) & I still thought it was a warm sounding set up. I honestly do love the SLP05, but I don’t feel the same warmth. And again, that could be the tubes, except for 3 & 6 (the balanced ins), the other 4 are still the stock EHs.