Musical Fidelity Trivista 300 vs. kW500

Speaking of beating up on MF stuff, I love the KW500 throught some Thiel 2.4s except for the lack of bass. Something is wrong. Other less $ equipment plays the kettle drums and other base fine with everything the same but the int amp. EVERYTHING the same save the wall outlet. MF KW500 issue or it just needs repair??? I've even brought in my amp and hooked it up to the preamp out of the MF and it plays the base (but not the wonder detail and air in the highs).

Opinions? I'd love to take it home if it will just play drums and bass guitar, etc. Shop says I'm FOS, that thier $7000 amp that they can't sell for years and years plays base fine, but it clearly doesn't. They won't sit in the room and listen with me long enough to hear the passages where the difference is so obvious (always some mega deal phone call or customer coming in by the time the cables are all moved over). I just want to know if what I'm (not) hearing is the amp's deficiency or what!

I can't remember the interconnects. They are using Kimber cables to the speakers and the 2.4s don't seem to be the problem. The ones at the store sound close enough to the same (on my amp) at the store and as my 2.4s sound at home on my amp. They've got plenty of detail and base short of the really deep base + LFE ranges.

Maybe, but they are proud of the Kimbers and the other 2 amp have bass-a-plenty through them and the same speakers that the MF doesn't. The only thing changing between using my amp + MF pre vs MF amp + pre is the addition of cables from the pre-amp to my amp and the amps. So it's in the KW amp part of the integrated KW500