Hi. I owned a Krell FPB 300 and here is the pre-amp progression I went through. Started with Krell KSP-7B. Replaced with Krell KRC-HR. Replaced it with Krell KRC-3. Finally replaced with ARC LS-25 MkII. I liked the ARC LS-25 MKII driving ProAc Response 3.5 and then ProAc D38s best. Best mid-range, more air in treble range. The best Krell was the KRC-3 IMHO. It's a current source product like the FPB amps. Put a good power cord on it and connect it to a good power conditioner and you have a really good solid-state pre. The Krell combination had great bass.