Step-up transformers...

I have the Benz ACE M like you and still do. When I was using it mated with the Wright WPP100C, I used K&K Audio (Lundahl L9206)step up trannie. The trannie can be hardwired into 1:5 (14 dB), 1:10 (20dB), and 1:20 (26dB) depending on your application. Info can be found here:

http://www.kandkaudio.com/phonostage.html

and their exclusive forum if you have some concern that needs some addressing is here:

http://www.audioasylum.com/forums/KandK/bbs.html

I do not use a trannie anymore but I still have it. My Supratek preamp has a lot of gain so the trannie becomes un-necessary. I kept it because it sounds great to me and hoping that someday I can use it again. Mine is not for sale BTW.

Check the links above. This might work for you.

If you can stretched your budget a little more, here's another one:
http://www.bentaudio.com/index2.html
Although the Bent cost more money.

Both of the step up trannies are more than adequate for the job and sounds great from my experience.

Happy holidays!

While I'm sure there are other good options, I would second the Bent Trannies. I don't own them but I once borrowed Doug Deacon's and they were awesome. I'm sure Doug will chime in with advice at some point.

On the other hand you might just consider a preamp change. I have a Shelter 501 cartridge which also is .4mv into a Plinius M14 solid state phonostage with MM and MC gain and a LAMM LL2 tube preamp. I prefer to use the MM gain in the phonostage since the LAMM pre has fantastic detail and dynamics and low noise and also using the low gain gives more adjustment range in the preamp volume control. With MC I typically stay below 10 O'clock position.

try the quicksilver transformer.
gregadd