Comments on Mark Levinson's 380 & 380s used.

The "S" Version are always better. If you get the 380, it'll cost a few grand to update it in the future. I have the Hovland HP-100. BTW, your CD player will be the weakest link in your system.

I have owned a Mark Levinson 380 for several years. I have used it with a 332, and also with two 332's biamped. I am using it now with a set of Levinson 33H monoblocks, and a Wadia 861 cd player. It is a great preamp, that I could highly recommend, and should match up wonderfully with your 336.
The 380s is essentially the same preamp, with higher grade components. It will cost you a little more money, but if you can spring for it, it will save you thousands of dollars in upgrading the 380, if you should decide to do so. I think that the last time that I checked, the upgrade was between $3000.00 and $4000.00, if you wanted the new face plate.
If you can find one, you should be able to pick up a 380 for somewhere around $2500.00, but a 380s will probably run another $1000.00, or so. I have been very pleased with mine. I have had it for several years, and in several different systems.