I have a Nuforce st200 amp with Zu Omen Defs. When I was waiting on my Rogue RP-5 Pre to get repaired, I use my Pro-Ject S2 Dac as a pre (only digital inputs). I was really impressed how it sounded. In fact, if it had all the analog in's, I would probably be happy enough. Anyway, Pro-Ject has this preamp http://www.audioadvisor.com/prodinfo.asp?number=PRMAPRE. AA has a good return policy. Overseas, (the Pro-jects come with universal plug adaptors for power any part of the world, this pre looks tempting: http://www.audioaffair.co.uk/pro-ject-pre-box-ds2-analogue-pre-amplifier?
This Preamp has gotten decent reviews: https://www.google.com/search?q=Nuforce+preamp&rlz=1C5CHFA_enUS721US721&source=lnms&tbm=...
Good Luck
This Preamp has gotten decent reviews: https://www.google.com/search?q=Nuforce+preamp&rlz=1C5CHFA_enUS721US721&source=lnms&tbm=...
Good Luck