What's your budget?
If you have $3+ K to spend I highly recommend Opera-Consonance Cyber 800 tube mono blocs deliver about 80watts per channel. That is the discount new price. Not too many used around.
What amp do you use with your passive pre?
I decided to get a LDR Passive Pre. No, not Tortuga. This one is from a super nice guy name Chris in New Zealand. I currently have a Class D amp (one of those better boards). Although I like it, I always miss the Class A/tube sound. So, looking for amp that is minimum 50wpc. I currently have 91db speakers but will change them soon to Harbeth (most likely).
Long story short; what amp are you using with your passive pre?
Long story short; what amp are you using with your passive pre?