which tube pre-amp good for Jeff Rowland model10?

I also have a Model 10 in my system and have owned a number of preamps both tube and ss; Audio Research LS25 MK 11, Conrad Johnson 16LS Series 11, Placette Passive preamp, and a Jeff Rowland Synergy 11i. In my system the best match was and is the Conrad Johnson. It remains in my system and I have no immediate plans of changing.

Could you please describe more about what it sounds like with CJ 16SL? I've heard CJ tend to be warm and ARC sounds more neutral. Thanks!

I should preface this by saying that I have had tubes in my system since the 1960's so I lean toward the tube sound. The Model 10 to my ears is the best ss amplifier I have heard. It is articulate, detailed and full at the frequency extremes but it is not tubed and I feel that a tube pramplifier matched with the Model 10 is the best of both worlds.While I found the Audio Research LS 25 an excellent preamp it was to analytical for my taste. On the other hand the Conrad Johnson is not only detailed and musical but adds the tube warmth if you will to my system. Now the CJ is not tubey sounding in the way of the old 1960's preamps. It is a modern tube design and can compete with any current preamplifier in overall dynamics and sound reproduction. Hope this helps a little, trust your ears and if you can try different preamps and see which one works for you.