Mark Levinson 326S or Audio Research Ref 3 ?

I have a Threshold Fet 9 preamp which I want to change. I bought this one years ago and choose it because I thought it would temperate a little bit the energy of my power amplifier an OCM 200 which is very fast and almost a little bit agressive sometimes. (Londspeakers are Infinity Renaissance 90).

Now I want to upgrade my preamp and I was thinking at the M.L. 326s or the A.R. ref 3 ... what would you advice?

Thanks for your help.

Regards