Tube or SS Preamp with electrostatics & ML amp?

Look at the Blue Circle line. Blue Circle owner/creative genius Gilbert Yeung uses Martin Logans in his reference system.

Did you consider the matching preamp from levninson?

I would check out a Conrad Johnson PREMIER 3 goes well with SS amps and Martin Logans.Had that combination but with a THRESHOLD amp.Cheers.

What is your source? Do you have more than one?

If you only use digital, there are a number of CD players out there that do incredibly well without a preamp. The Audio Aero Capitole (my favorite) or even the Levinson 390S. I am a dealer for the Audio Aero so I am attempting to offer other alternatives as well.

This solution saves on cable runs as well as power cords. It also, to my ears has a greater level of clarity without loss of dynamics. In this case, less is more.

Go listen for yourself and let us know your thoughts.

Krell KRC-HR - there's a used one here for around 2600 and a great preamp, the best they made until the newer models. It has balanced ins and outs, and would match well with the Levinson I presume.
I believe with your amp it's best to go balanced. The ARC LS-25, or BAT VK3 or 5 or 40 would also work well.