Tube Preamp Question

I recently added a JM Audio Peach II to my Klipsch RF-7 based system and I have a few questions. My initial impressions are that the Peach adds a sense of depth to the soundstage and makes vocals more prominent (what I was hoping to achieve). I however have also noticed that it softens the attack of the snare drum and the bass sounds more rounded (this is what I have read may also happen)
What I did not expect was that the soundstage width would be decreased. Is this typical?
The center image is very strong and the sense of depth is great but everything is happening front and center.
Even more surprising was that while in HT Bypass mode the “tube sound” is still present. I tried to listen to a song thru the Peach II and then through the Rotel receiver in “HT” mode and the Peach II certainly sounds better but I don’t think the Rotel sounds the same as it did before the insertion of the Peach. Are tubes in the path during the “HT” mode? Could anything else account for this phenomenon?