anyone ever install two different models/types of jazz bass pickups in their j-bass? i'm thinking of doing this with a dimarzio model j and a dimarzio ultra-j. any thoughts?

No thoughts yet. Can you tell me what it is you want to accomplish? Also, where are you planning each pickup? Is there a plan, or do you just have a couple of pickups lyingh around?

FWIW:

I've mixed pups on a number of occassions. I've got a bass on the wall right now with an LP soap and Epiphone soap. I've mixed actives and passives. But I run stereo straight out seperate jacks so there's not an issue with incompatibility - actually one exception. I'd guess even through the typical onboard harness actual incompatibility wouldn't be that frequent. What's more likely is the tones won't work together - but that's frequent in matched pairs as well.

Depends on personal taste but in general I prefer a fat bridge pup and thin neck pup cuase I favor the bridge. But a significantly higher output bridge pup will balance volume more uniformly. I'd also guess that an onboard preamp would tend to mitigate incompatibility as they tend to mitigate everything else.

Never actually had those Dimarzio's but it sounds like the J at the bridge and ultra at the neck has promise - unless you like it dark.

i don't like it dark, i'm trying to compensate for the lack of mids in the ultra jazz, and the lack of treble in the model j.

i don't like it dark, i'm trying to compensate for the lack of mids in the ultra jazz, and the lack of treble in the model j.

FWIW:

may work for you then. Positioning won't change the characteristics of the pup but will accent some over others. A bridge pup will become darker, softer, less defined, and louder the further up the necks it's moved - and visa versa. It's earsier to darken a bright pup than brighten a dark pup (just as it is with acoustic properties of a bass).