Mark Levinson 38S vs 380

I bought a pair of ML-434 mono-blocs this week.
Now I would like to upgrade to a ML pre-amp.
Im going to buy used here on Audiogon.
I would like to know which is the better pre-amp between
the 38S and the 380.
I understand that the 380S is the best of the series,
but its out of my price range at this time.
I know that the 38S is better than the 38,but with the 380
being newer that the 38S, IS IT BETTER???????
MY SYSTEM CONSIST OF:
Pre-Amp: Adcom gfp-750
Amps: Mark Levinson 434s
Dac: Theta Pro-Basic IIIa
Transport:Theta Pearl
Cables: Kimber Select KS-1120(pre to amp)
KS-1111(source to pre)
Kimber Orchid(XLR dig)
Thanks,