Hello All, I'm not a tech guy, but my dad is gaining knowledge in this area as he is pursuing luthiering in his retirement. So I'm sort of asking this question to pass on to my dad as a jumping off point or a broader spectrum of possibilities from those of you with more experience. I bought a Bart Preamp from a TB'r a few years ago and have it currently installed in a Warmoth (Alder, Maple, Pau Ferro - sonically sounds/feels great) with a Bart jazz neck pickup and a soapbar bridge pickup. The preamp was hooked by a local luthier who is respected and does great work, but is a guitar player, not a bassist. The bass sounds goods, great in fact, and most people wouldn't think anything was wrong by just plugging it in and thumbin' around. However, in a live or studio situation, it is bright and thin in the mix. NOT crazy thin, but thin enough to where you notice a definite difference when any other bass takes its spot and suddenly the bottom is there. I've played it in many live situations and most of the time have put it away and used my back up bass instead because it just doesn't fill the space that it is supposed to. In the studio, an engineer had me crank the bass and completely mute the treble (roll it off all the way) to get somewhere near a decent Fender tone in the mix. I've owned a number of basses and never had a studio guy struggle with any of my basses like that. (It had a two j's in it at that point, no soapbar.) So I have been prone to just getting a new preamp (or pots maybe) to see if that helps, but don't want to make any moves too quickly, as it could be a simpler fix. Does anybody have an idea of what the 'subtle yet disheartening' issue could be. Looking forward to staring blankly at your technically informed answers, and relaying them to my ol' man like a boss.