Thanks for all the suggestions and insight.
perhaps I should provide a bit more context of my set up and room situation.
My set up is::
PS PWD Dac =>Joles Electra LA-150MKII => Ampzilla 2000MKII => Celestion SL600; McCormick DNA 500 => Celestion 6000 subs
The Celestion sl6000 system is a monitor+di-pole sub combo, where the monitor is a SL600 and the 6000 subs; So I pretty much have to bi-amp.
My set up is in a dedicated music room ~ 22x26x8 with a fair amount of sound treatment. I have 2'x6' bass traps in 3 corners of the room and sound panels in the other four walls.
I did move the bass traps out of the corners of the room to test things out. There was more bass, but not the slam level that I'm still seeking. To be clear, it isn't deep bass I'm missing it is that slam factor as mentioned above.
I recognize the Krells are know for slam and dynamics but the Ampzilla and McCormick had been know for being high current amps too. This is why I'm some what puzzle especially because my friends amps were just 100w & 200w krell's and the Ampzilla is 300W and the McCormic is 500w into 8 ohms.
I had ran the system using my PS PWD direct into my amps just to make sure the Joules Electra was not the factor as the Joules is a tube pre. There wasn't any noticeable loss of bass when I had the joules in the path, so it stay.
Both the McCormick and Ampzilla had served me well with many hard to drive speakers including ribbons and electrostats. I'm some what stun that a cone speaker would be tame by these beastly amps.
Do Krell's really have such dominance in the slam department that even well design amps such as mine are not in the same league?!
Would love to hear from someone who has heard my amps and Krell's to tell me if I'm just going down the garden path here.