Would have to agree with Shakey. Passive preamps did in my SLP-98 and Joule Electra LA-100MkIII, as well as a couple others.
I had the SLP-98 mated with my V12i and while there is definitely synergy, IMO it was too much of the Cary house sound for me. The Joule alleviated that, and had better frequency extension.
As for 6SN7 designs versus the smaller signal tube designs, there is a lot more to it than the tubes. I have had both types of designs in my system and while I think highly of the sound that 6SN7 tubes can deliver, I've quite enjoyed a number of 12AU7, 12AX7, and 6DJ8/6922 tubes as well.
I had the SLP-98 mated with my V12i and while there is definitely synergy, IMO it was too much of the Cary house sound for me. The Joule alleviated that, and had better frequency extension.
As for 6SN7 designs versus the smaller signal tube designs, there is a lot more to it than the tubes. I have had both types of designs in my system and while I think highly of the sound that 6SN7 tubes can deliver, I've quite enjoyed a number of 12AU7, 12AX7, and 6DJ8/6922 tubes as well.