best amp for BASS

FPB 300 or FPB 600 KRELL

Krell FPB300cx or FPB400cx (what I use)

I'm partial to Steve McCormack's DNA-2 Revision A amplifier.

There's something spectacular about the bass when using XLR connections thru-out with this particular amp. I've used XLR connections with other amps, including my very highly rated McCormack DNA-2 LAE(Limited Anniversary Edition), but I've not witnessed anything close to what the DNA-2 Rev A does with those 2 additional volts from the XLR connections.

Regardless of which amp you select, you most likely would be better served if you use XLR connections. With XLR connections, the dynamics and bass are most always at least a bit better reproducing just a bit more of that live bite.

-IMO

Bass response is HIGHLY dependent the on the room and where the speakers are placed in the room . What you perceive as an amp issue might be resolved by repositioning the speakers or room treatments. Throwing money at the problem by buying better equipment will only take you so far. Since money does seem to be a major concern, you may wish to seek professional advice on room treatments and speaker placement.

If you like YBA, Krell may not be quite what you expect although it does have tight bass (the 600s on Wilson Sophias). FWIW, I had a Krell KSA 100 for a while and it was good but a little bright.

I liked the McIntosh MC1201 monoblocks the best however, slamming massive McIntosh XRT28 speakers like I have never heard before. Everything was shaking except for the amps and speakers (they weigh incredible amounts). I was impressed but it's a conservativly-rated 1200W per channel amp afterall. At any rate, try to audition whatever you can because room and system synergy are critical for any new component to sound good. Arthur