My interface has a DI and it has a switch. Normally you use it switched in for electric guitar. But if I used a stand alone pre amp or something like a Boss 1000 I would go in a 1/4 inch jack on the back instead because its already line level. I was wondering if I didnt switch the DI in...would it be ok to go in the front with a separate pre or any box that has some kind of signal boost in it.. many devices do.... I know this is a tech question but you probably know what I mean.... I am trying to get a better knowledge of elec. and signal stuff... all part of the recording process....thanks as always for your knowledge..

The answer depends on the specific interface you're using. Some interfaces can accept both DI guitar signals and (hotter) line-level signals via the same 1/4" jack, as long as the switch is in the correct position. Others might have one jack dedicated only to guitar DI and a second jack for line-level signals. Let me know what the brand/model of the interface is, and I should be able to find the answer in the docs. Of course you could try it—you wouldn't hurt anything, but you might get a distorted or less-than-ideal-quality signal if the front (DI) jack isn't meant to be dual-purpose. But it should be simple enough to look it up and be sure.. The video below explains in more detail (the section most relevant to your question starts around 2 minutes in)..

mine is the SteinbergRT2 with a switch on the left front mic input.

Ok, with the Steinberg UR-RT2 both 1/4" jacks on the front can be used as standard line-level inputs (in addition to line inputs 3 & 4 on the back)—all accept balanced (TRS) 1/4" cables. If you push in the Hi-Z button on the front, then Input 1 (only) will function as a DI for electric guitar/bass, as long as you use an unbalanced (TS) 1/4" cable (the button shifts to the higher input impedance required for EG/bass DI). See page 6 of the manual for more detail on the line inputs & Hi-Z switch and appropriate cables: http://download.steinberg.net/downloads_hardware/UR-RT2/Manuals/UR-RT2_UR-RT4_Operation_Manual_en.pdf