don't get an active DI, if you are ditching the modern amp, you don't want an active DI, it's the modern sound. the passive DI will have a transformer that will give you a little coloration, like a good tube amp would (nothing close, but the parallel exists). passive DI with passive has been happening forever and is the sound of so many hits and records you love. Motown had the Wolfbox, Sigma Sound in Philly had/has their Sigma DI, and on and on.
The passive bass needs active DI is an invention by the music companies to get you to buy more poopie, its bunk. Also its a lot easier to have a bass, tuner, passive di all in your case/gig bag when you go to the studio instead of hauling power supplies for active di and stuff.
The JDI might give you a TINY bit of coloration but it's really designed to have a flat frequency response. From the manual:
"The JDI is very unique in that it does not color or alter the sound in any way. This ensures that natural tone and harmonic balance is retained, bringing out the very essence of the instrument."
To be fair, this might not be entirely the case. I personally think there is a very slight coloration of the tone with the JDI, and a pleasant one at that. But the JDI is most definitely not designed to color the signal and give you a "vintage" tone. In fact, many active DIs (that can also have transformers btw, or even tubes) can give you far more "vintage" coloration than the JDI and also offer potential benefits with passive basses in some situations. To make a blanket statement about active DIs having a "modern sound" is quite simply wrong.
It's also wrong that you will need to "haul power supplies" for active DIs (tube DIs excepted). An active DI will usually not take up any more space than a passive DI, and with the exception of tube DIs it will be powered by phantom power, which is available everywhere there is a PA/mixer/micpre/audio interface.
My point is, any tonal coloration isn't necessarily about active vs passive, but about what the DI box in question is actually designed to do. Some DI boxes are transparent, some are colored. And althogh the JDI may not fall into the ultra-transparent category, it won't really give you a colored, "vintage" tone either.
Even with something like the Motown Wolfbox any coloration would be pretty much negilgible compared to coloration from the rest of the recording chain they used (tube gear, tape recorder). This coloration wasn't a deliberate choice of course, but a result of the technical limitations of the recording gear that was available at the time. In retrospect these technical limitations actually provided a sound that, at least in SOME ways and for SOME styles of music, can be perceived as more desirable than the ultra-precise recordings we can make with digital gear today. But the fact that they used a passive DI box had practically nothing to do with it.
FWIW I find that the cheaper Radial ProDI is slightly more colored than the JDI, with a slightly "warmer" tone. The ProDI might actually be a better choice than the JDI if more coloration is desirable from a passive DI. But it's a very subtle difference. Ultra-cheap passive DIs from other manufacturers can have even more coloration, but usually not in a good way (IMO).
Don't get me wrong, I absolutely agree that you don't NEED an active DI with a passive bass. You may even prefer the tone you get with one specific passive DI. But active DIs definitely have some advantages with passive basses, in SOME situations. And any vintage/modern tonal coloration will depend on what the DI box in question is designed to deliver, not whether it is active or passive.
