The preamp is definitely a Bart NTMB, the switch appears to be either a humbucker/single coil or series/parallel switch (easy to be certain - put the switch where the tone is "thin", solo the bridge pickup, take your hands off the bass - buzz? single coil; no buzz? parallel

).
Greg is correct, our "stock" pickups on the Custom (which this is) and Signature series basses are indeed quad coils. The Standard/Standard Plus models have CB's, which look identical, but are not quad coils.
Nice bass!
Gard, thanks for the clarification as well! I'm thinking the switch is a series/parallel switch, I haven't heard any buzz from the bass at all with the bridge pup soloed, and I've tried all of the configurations in trying to figure out how this bass sounds.
Not sure why he told you that, those two preamps are night and day. The Demeter has much tighter lows and smooth highs and a scooped mid, the Bart tends to color a lot in the lower and upper mids.
In my Century 5 JJ, I added a special Demeter preamp James made for me, I had a set of Fralin's in there but they are just a little to clean for the Demeter so I put in a set of the Aguilar's. I would really like to try a set of the Nordstrand NJ5FS pickups as I have heard they have a little more punch than the Aggies. My Century 4 has Roscoe/Barts with the two band Aggie preamp, which is just a little too nasal on the G string so I have a Demeter being built which should come in sometime this week.
I remember it like it was yesterday, and honestly, he seemed a little put off that I would ask for the "Roscoe-spec'd" pre for a different bass. I won't judge, maybe he had a bad day, he was pretty short with me when I called him
I had heard a lot of good things about the Roscoe Demeter pre back then, and was thinking about throwing one in my project bass, to pair with the Bart CB dual coils (I still have them in a box lol). Do you think you could record a clip of your bass with the Demeter installed? I'd be really interested in how it sounds.
My guess is, since that Bart pre was one of the first after market active pre's available, most designers of later units would have probably been influenced by the general design, while not necessarily achieving similar tonality.
I'm actually very impressed with the stock Bart pre in my Signature. Hadn't played one in decades. Powerful, aggressive, and quite usable. Sounds great set 'neutral'. I usually just boost the bass about 10%, and for a more fat tone on some tunes, favor the neck pickup and then boost 800hz mid setting slightly for definition/articulation and a bit of growl. Nice! The only negative for me is the lack of a bypass option, which is just a nice 'peace of mind' thing in case something goes wrong.
I suppose that makes sense, I haven't been playing bass long enough to know first hand. Bartolini is one of the strongest custom/aftermarket pickup and preamp manufacturers for a reason, and I can definitely see other designers taking their cues from them.
My old project bass had a similar iteration of the Bart pre, but I sold it a year or so ago, and that bass wasn't all that great lol. The pre in my Roscoe, in conjunction with the pups and wood config, is great IMO. I used to swear by Aggie pre's, and they're awesome in their own way, but I like the darker sound of the Bartolini pre. I've discovered a few sounds that I like, and they go from really smooth, to really aggressive, all from one preamp. It's especially fun when I solo the bridge pup, pull my mid knob out (sounds like it's switching between 300hz and 800hz) and boost it up a quarter turn and crank my treble. Both fingerstyle and slap, I'm really starting to dig it.
I did my setup last night. I noticed the saddles were almost all bottomed out, I could only make very small adjustments to the string height. So I tweaked the truss rod a bit....quite a bit actually since the bass was sitting in a case for a year in the heat. I normally set my relief at .015mm at the 8th fret. The Roscoe can go even lower without any string buzz, which I think is cool. I may tweak it again tonight just to see if I can get it to that super low, breath on it to play action.
I love my Cirrus, especially after I upgraded the preamp to the Pope Flexcore (I highly recommend this preamp!), but it's nice having another high quality bass that is still aggressive, but covers a different tonal spectrum

