When plugging my Warwick Corvete pro GPS (active PU/active preamp) into Warwick amp (normal input, or in return input to bypass amp preamp), Sound is OK when I bypass preamp on Bass. When preamp is active, Sound iz hollow, mellow, like out of Phase. No matter wich pickup or blend of them is used. Output Volume is not problem - its the same in both Cases. But when plugging Bass into Scarlett interface, opposite is true - muddy, hollow sound in pasive mode, and growly and full in active mode. Both listened through Bayerdynamic DT770PRO Headphones. Seems like some weird phase issue, but what puzzles me is different behavior with different input devices. I have also a Sire V7 Bass. Sounds OK in Scarlett both passive and active, but in Warwick amp it sounds hollow both passive and active. I tried for test inverting polarity of cable and that cured the "phase issue", but that introduced some noise in signal so its not usable that way, but sound did get "in phase". Same "reversed" cable on Scarlett interface - Phase issue. I also have modified Squire Bass with MEC active PUs and preamp from early 90s. Bad bass/trebble pots gives me trouble so i bypased (resoldering) preamp so only volume and blend pot are in use. That is the same as if i pull volume pot on Corvette to bypass preamp and that Squier behave exactly the same - sounds good in Warwick amp, but with Phase issue on Scarlett interface. EDIT: FWIW, on both Warwick and Sire bass, when in passive mode (on Warwick PU stays active, but preamp is bypassed), measures of output jack is 7-9kΩ, and in active mode 95kΩ Can someone explain this to me? Is there a problem, or is it "a feature"?