Seems fairly straightforward, right? A 1/4″ cable connects the instrument to the DI box. Is there really a right and wrong way to do this?
As far as sound quality is concerned, no. There’s nothing more to it than plugging into the correct jack. The difference I’m talking about is whether or not you cause a loud “pop” in the system. There are two connections to be made: one at the guitar and the other at the DI box. And the order in which they are connected determines whether or not you get a “pop”.
HOW TO STOP THE “POP”
When plugging in, plug in the guitar first, then the DI box.
When unplugging, unplug the DI box first, then your guitar.
Musicians, if you need help remembering the order just think “it all begins and ends with my instrument.” Now, don’t let it go to your head 😉
Techs, if you need help remembering the order just think “it’s not my gear that causes the pops, it’s those darn musicians.” Now, don’t let that affect your attitude 😉
[For bonus points, recall the proper order for powering consoles and power amps. The console goes on first and off last to avoid a “pop”. An instrument and a DI follow the same sequence, just further up the signal chain. Something to think about…]
I will give a caveat: as much as it sounds like a fantastic life goal, I have not personally tested every DI box, let alone every acoustic guitar, keyboard and bass guitar. Having said that, in my experience the sequence above also prevents pops on guitar amps, preamps, amp simulators and all other kinds of equipment. So test it out with your own gear before you’re in a performance situation.
One more thing: if you have a good stage policy, teamwork, and you’re hitting your transitions, you should never have the opportunity to induce a “pop” into the system. Your input should be muted at the console until the instrument is plugged in. This sequence above is more of a fail safe, but one that’s a really good habit to get into.