Tube preamp recommendation for a simaudio 760a amplifier

Hi Folks,

I'm looking for a new tube preamp for my 760a amplifier. My Don Sachs tube pre sends it into dc protection mode. According to Don and my tech, this amp is too sensitive for this preamp which is capacitor coupled.It just leaks too much DC at the outputs.  I love the sound but it's just not jiving. I'd probably need a transformer coupled preamp. I like a warm detailed sound. 

Thanks in advance!