Best phono-pre for mc-systems below $ 1.500,00 ?

Try the decware; it is just over 1500 equipped for both MM and MC. Decware offers a 30 day money back deal if you don't like it.

EAR 834p moded. Mitch Singerman's mod for example.

Agreed, I ordered the Decware and will be comparing it shortly to a Whest PS .20 and Hagerman Trumpet, both list priced at $1000 over the Decware, but available used within your budget in the case of the Hagerman. A lot of people like the EAR as well, which I believe is also just under $1500 new. However the MC gain was too high for me (72db).

If you want to only spend 500 check out a Dynavector P75; excellent value for the money but not in the same league as the ones mentioned above.

The new JLTI phono pre from Allen Wright is in your budget range. http://www.customanalogue.com/jlti_phono_stage.htm

I have one and swap it back and forth with my Herron. After hearing mine, a friend bought a JLTI to replace his modded Threshold. I am hoping to do comparisons against the Whest and EAR, but have not had the chance yet.