pass or levinson

Hey all,

I'm considering an upgrade at the pre level. Up for consideration is the ML 380s or the pass labs x.1 or is it x1 X1?
It will be in use with the Meridian 508> Harmonic Teq magic link II (xlr)>levinson 38S> HT mlI(xlr)> Pass labs x350> HT pro 11 (temporary)> Thiel 3.6.
My question is would the upgrade be worth the money spent? And which might offer the greatest benefits as far as surpasing the ML 38S in sound quality?
I wholeheartedly recommend the Pass X1. An outstanding preamp, especially for the money.