Primaluna Integrated with a seperate preamp


I have a Primaluna Dialogue Premium Integrated amp . I wanted to know if anyone has used a separate preamp through the H/T input which has a unity gain circuit .
What affect would the unity gain circuit have on the preamp signal ?

Thank You .
saki70
Odyssey7 I agree the PL power amp is fantastic on its own. I have found Winged "C" EL34 tubes offer the best overall sound IMO. The Gold Lion KT88 also are very good but if one prefers EL34's the Winged C's are the shiznit or at least in my system.   

I started going the separates route and ended up with a BAT VK55 amp and VK31SE preamp. Fantastic combo however, I am chasing down the right power cord combination but getting close. I will try the BAT VK31SE soon with the PL to see how it mates up. From your review of the Don Sachs it sounds like it is one hell of a unit and obviously compliments the PL very very well?  After using the LS-26 mentioned in my above post I was thinking the PL didn't respond well to a separate preamp.  
I realize I'm way late to this party, but I just picked up a DBX DriveRack PA2 to correct some room and speaker shortcomings and I'm doing some connection research.  I've been told that connecting the DBX as an aux input into the Dialogue Premium Integrated is not optimal.  Would installing this DBX equipment be an occasion to connect to the HT bypass?