The PDI 03 JB became my go to DI box for guitar. This has been the case for years now, and I tried them all - not counting reactive loads and IRs - and always turned back to this piece of gear special to me.
What I like about it:
- fully passive and rugged. No bs battery, LED, power plugs. Just plug and play with your amp and cab or load box.
- 3 levels of sensitivity. You can use it with power output or just with pedals, at preamp or line levels. Really handy, easy to experiment with even without a power amp!
- it sounds full, punchy, not noisy.
- versatile EQ. It can go from smooth dark to piercing bright, and from mid scooped to mid-forward. Also three levels of low end resonance. The controls are interactive and it is really hard to not get a tone you like or the one you need out of it, for both guitar and bass. The "JB" switch provides a new dimension: I think the original model lacks the mid push typical of a guitar speaker by itself (it has more of a bass speaker frequency response), and this switch puts it back into place.
- all the other features that you need in a DI, nothing more, nothing less: ground lift switch, unbalanced and balanced outputs.
What I would add or change to it? Very little!
- I would make the JB settings more different from each other: the Medium and Heavy don't differ very much from each other, the difference is subtle. But it may be just in combination with my typical rig or settings.
- a switch to disable speaker emulation altogether would have made it universal :D