DiMarzio DP123 Model J

Pickup features: Jazz style humbucking bridge and neck pickups
Impedence or other specs:

Model of guitar or bass: Yamaha BBN-4
Position: neck
Pickup being replaced: both bridge and neck stock pickups
Other pickups on guitar: none
Artists using this pickup: Anyone who values great tone!
You musical style(s): Heavy rock/funk
Reason for pickup change: The stock pickups in the Yamaha bass are good sounding, however, they are single coil and as a result, hum unless both volume controls are wide open.

Perceived output level: These pickups are great! By using DiMarzio's series/ parallel switching, you can sound like a jazz (growly sounding) or a rickenbacher/ music man (punchy funk/clean solo)
Tone: these pickups certainly growl in series position. Sounding very much like a vintage jazz, or even a P-bass with guts. In parallel, these pickups take on a glassy character- very clean and neutral sounding, which would be great for slapping or tapping (ala Stuart Hamm). You do need a little more gain in this setting however.
Sonic evaluation: I use each pickup into its own amp (stereo, just like the old Chris Squire/Geddy Lee Rickenbacher sound). I run separate FX loops for each. Bridge gets some distortion and chorusing form time to time while the neck gets a little (read: killer!) bottom end from an octave pedal. These pickups cut! I have to contend with two guitarists, each with a 4x12 cabinet on stage. I use two Gallien-Krueger 400RB heads, one powering an SWR 4x10 and the other, a 2X10 cabinet with old Ampeg drivers. with this bass/pickup/amp combination, there is enough lower mid/bass punch to cut through the guitars at just the right frequencies without burying them (and the other way 'round as well!).

For which styles and positions is this pickup (un)suitable: I play mainly a heavy version of rock that sounds like Metallica meets The Spin Doctors (or even Danko Jones). I like the separation of my bass running in stereo, rather than mono (mono tends to dull the pickups top end). If you have the means to do so, wire your bass for stereo- otherwise, they still make great QUIET replacements for you Fender Jazz style bass!

Comments: I would IMMEDIATELY replace these pickups if they were stolen! Of course that means the bass would probablyhave been taken as well. So whoever tries might end up with broken fingers!!!!
I've been playing over 18 years in studio, stage, and clubs. Like I said before- the Yamaha single coils just weren't doing it for me, so in went the DiMarzio DP123s! The instructions were clear as day and the soudn is AWESOME!!! Comparing the price to a lot of (overpriced!) pickups on the market, these are an incredible deal!!!

Pickup features: passive humbuckers
Impedence or other specs:

Model of guitar or bass: fender jazz
Position: neck
Pickup being replaced: original fender set
Other pickups on guitar:
Artists using this pickup:
You musical style(s): jazz, stds, r&b, latin, swing, mor
Reason for pickup change: looking for a better sound

Perceived output level: same or more than the normal fender jazz stock output
Tone: a pickup that can be adapted to any music I play
Sonic evaluation: fender jazz, gibson acoustic bass, swr, acme, carvin and canadian yorville amps, acoustic image amp, sadowsky outboard preamp, trace elliot tube preamp. I combine the gear for the night from these.

For which styles and positions is this pickup (un)suitable: jazz, stds, r&b, latin, swing, mor;

Comments: these pickups have the tone, growl, output that surpass all the passive and active ones I have tried. and i have tried a lot. just like the basses, you still go back to the fender jazz. take it from me, take the short cut, a fender jazz and dimarzio 123's.

Pickup features: split coil humbucking laid end to end in jazz packages, passive
Impedence or other specs:

Model of guitar or bass: Fender jazz mexican
Position: neck
Pickup being replaced: both stock jazz pickups,
Other pickups on guitar: no other pickups
Artists using this pickup: the artist formerly known as "me"
You musical style(s): jam, blues, rock, freaky, styley
Reason for pickup change: The stock pickups were not humbucking.

Perceived output level: little louder than the stocks
Tone: pretty standard sound, sounds more like a modern dual pickup bass now
Sonic evaluation: Sounds good. I turn down the tone for a more low-fi sound. When both pickups are on, it gets a hollow kinda growly tone.

For which styles and positions is this pickup (un)suitable: all

Comments: I'm satisfied. They are much better than the stock hummers. They've got a good sound. I had to break out the wood chisel to fit the larger bridge pickup into the route on the body, but no big deal.

Pickup features: split humbucker, passive pickups, ceramic magnet
Impedence or other specs: 4 conductor, DC Resistance: 7.76K

Model of guitar or bass: 1997 Squier Jazz Bass (Mexican made)
Position: all positions
Pickup being replaced: stock pickups (something really cheap)
Other pickups on guitar:
Artists using this pickup: any Jazz Bass user who cares about tone
You musical style(s): rock (punk to metal, pick and fingerstyle)
Reason for pickup change: Unhappy with stock pickup sound. Drowned out in mix (one guitar and loud drummer). Needed something with more definition and bass.

Perceived output level: according the the manufacturer, the output is rated 150 Milliwatts...higher than a normal Jazz Bass pickup but not high enough to be consider a hot pickup....my ears tell me that this thing is loud!
Tone: according to DiMarzio, the sound is as follows: Bass: 6 Mids: 5 Treble: 4 From my own two ears: thick ass bass and cutting mids with rolled off treble...wonderful tone!! sounds pretty balanced to me...makes my cheap Squier beat the living shit out of all American STD Jazzes out there! No kidding, these pickups are fabulous!
Sonic evaluation: you already know the guitar, but my amp is a weak Fender BXR 60 (I say weak do to the fact that 60 watts does NOT suffice when you have a loud ass drummer and 30 watts of distorted guitar blasting beside you). You should stick to a 4 to 1 ratio.....for instance, if your guitar player's amp is 25 watts, you should have AT LEAST 100 watts if you want any kind of presence in the mix......These pickups are fabulous, I really can't describe the tone aside from saying that they are much nicer sounding than the AM STD Jazzes that I've tried....warm, loud and they cut well in the mix....very smooth and bassy, try'em to hear what I mean.

For which styles and positions is this pickup (un)suitable: wonderful for rock (I do punk to metal), pick and fingerstyles sound great, can't complain about anything.

Comments: If my bass (with pickups attached) were ever stolen, I'd buy an AM Std Jazz, and buy the Model J's to put in...that must sound orgasmic. I've only been playing for about 2 years, but I know what tone I like, and this is definitely it! I love it's sound, I hate nothing. Although I haven't tried any other jazz replacements, the price and sound just did me in, I'm hooked for life. I've got "that" sound, or should I put it more correctly, "MY" sound.