Nope, it is true, as I said above - channel #1 has a decent mic' pre built in* (adjustable via a dial, with upto +40db of boost IIRC). That's why #1 is ideal for plugging even a low-output passive bass straight in to the mixer.
*I was/am also confused by stuff... until recently I didn't know that a mic pre is indeed the same thing as an instrument pre.
A DI box** is slightly different as I understand it - but you wouldn't need one of those either. ๐
** I'd only want to have a DI box to use as a splitter for recording... Here's a Beringer one for ยฃ16. https://www.thomann.de/gb/behringer_di20_di_box.htm?sid=8f1e42ac8833b0cb009cccd448b32ee6
It depends what you want to do mate, but I've been playing along with stuff, and then recording bass tracks, all evening, with just a bass, laptop, mixer, and headphones.
If you don't want to record yourself on the computer, I suppose you could achieve the same thing with bass, computer, practice amp (one with an Aux in, and Phones out), and headphones (or not).
๐