theL2500 was born to run in series and on the front PU or the PU's combined. this seems to be its sweet spot. the bass is very hot and bright but the highs can be dialled down to a nice balance. the bass sounds just as good in passive mode as well. custom shop quality in build. some of the best electronics out there and a very transparent preamp. the K mod option isn't a strong suit and is probably the least useful sound in the bass-you wont miss it. run it in series on any setting and you're there and will leave it there.