I appreciate the suggestions though it's definitely not just a volume thing. I'm predominantly a bedroom player (and tinnitus sufferer) so am pretty consistent with the volume across all my amps and the "thump" is very noticeably different at this same volume. Probably the most prominent thumper is my 5e3 Tweed Deluxe, though even my Deluxe Reverb Tonemaster (which is an all digital amp) gives me good thump, so it's clearly not just a tube thing.
I've also tried the Kemper through multiple cabs but with the very similar results thump-wise.
Long-shot, but has anyone at Kemper been looking into this?
It would literally be the icing on the (already tasty) cake for me