I had to send my BTB605MS back to Ibanez for warranty replacement, I waited until I received the replacement before making this post, to avoid having to wipe egg off my face in the event it was user error. However it wasn't. With only 1 month left on the warranty, the neck had warped backwards, slamming the strings down to the frets. No open notes would play, even with the saddles at maximum height, and the dual action truss rod maxed to add as much relief as possible. I felt confident that there was no mistaking the issue, I've dealt with warped necks before, but usually it's a slight twist, not a backbow.
Yesterday, the replacement (brand new) arrived. However, this one has an issue where the active volume is about twice as loud as the passive volume. I know it's not by design, because the one I sent in wasn't like that, nor is my BTB806MS which has the same preamp and pickups (albeit 6 string vs 5 string). I mean active mode on those basses were ever so slightly louder, but not double volume. I even used the same battery in the 605 and 806 last night to make sure the problem wasn't a dead battery. Both basses have brand new strings, and the same brand. I also compared the wiring to be sure everything looks the same on both basses, to ensure the 605 isn't accidentally wired in the +6db boost mode on the preamp, and it isn't.
I'm going to mess with it tonight, do some recording with both basses in active and passive mode. I expect when I do, I will see that the passive mode on the 605 is too low, not that the active mode is too loud, but we'll see when the meters light up and the DAW captures everything visually.
I suspect a bad solder joint somewhere in the passive tone path of the 605. I emailed Ibanez asking if there is an internal trim pot, despite me not finding one. If I do find a bad solder joint, I'll ask them if they will allow me to repair it without voiding the warranty. I would rather spend 30 minutes removing the nuts from the pots and fixing a bad solder joint, then wait for ANOTHER replacement, but I guess I'm getting ahead of myself.
This isn't a complaint post, I'm a big fan of the BTB series and have used them about 15 or 20 years starting with the BTB405QM, as well as Ibanez instruments in general. Warping necks isn't a new concept, it can and does happen from time to time, so can wiring issues. No big deal. The 806 I bought from
Sweetwater has been rock solid, probably due to their inspection and testing, so definitely don't let this spook you away from the new BTB's.