Check the manual. I have an active DI Box from Behringer (which for the 35 bucks works amazingly), and it requires phantom power or a 9-volt battery. Being "passive", Im not sure if that means it does or doesn't need an external power source. If it doesn't, make sure there is no decibal pad enabled - the Behringer has -20 and -40 dB pad buttons on it, and those automatically cut any guitar signal going into them. I'll take a look at the specs of this box later when I have a chance.

"Passive" DI boxes do not need or use phantom power. They use a special transformer instead of an IC circuit to do the "splitting". Are you "re-amping" your guitar tracks?

Yes if you get the chance to check the spec and get back to me that would be cool as the box also has a lift/ground switch and a phase invert/norm plus attenuator filter which uses a -20db and another -20db switch for some reason?? plus a filter on/off switch, which i have never used as i'm sceptical as to what it actually does to a recording any ideas anyone???
Thanks Goodge

Yes if you get the chance to check the spec and get back to me that would be cool as the box also has a lift/ground switch and a phase invert/norm plus attenuator filter which uses a -20db and another -20db switch for some reason?? plus a filter on/off switch, which i have never used as i'm sceptical as to what it actually does to a recording any ideas anyone???
Thanks Goodge

The specs say it works with "instrument, line or speaker level" signals. It may be a little confusing here, but that probably does NOT mean millivolt signals like a guitar pickup or unbalanced mic levels. (Neither of those are considered line level.)

You're probably not hearing anything because the signal coming out of you guitar alone may not be hot enough. (Along with those pads being selected as well...)

Instead of routing your guitar right into the box, try using a line out from your guitar amp's preamp out (or speaker-level output, with the correct pad-switch selected) to see.

If you can't get anything at all to come out of it, try some basic troubleshooting in the signal path:

1. Check the XLR cable going into your preamp/mixer/converter inputs. Plug a mic into it (preferably a dynamic mic, like an SM58 with NO Phantom power.) Does it work? Pass signal? if so, then mute the input on your board and unplug the mic. (You might want to turn down the input trim on your input as well, but NOT off...)

Next plug the XLR into the DI's output. (And of course, un-mute your mixer's input once you're patched in to the box)

2. Make sure all switches on the DI box are "out" or defeated. For now, set the box to completely neutral or "Default" mode. (No pads, no ground lifts, etc)

3. Try a line level source - like a CD player, keyboard output, etc. (Be careful if you use a SPEAKER-LEVEL output, it's going to be hot, and you'll want to make sure the pads are IN, and your mixers' input trim cut back...)

One of those proceedures should get you going. If you can't get any signal at all through the box, (and you've checked everything independently) then perhaps you've got a defective box. It's rare that it happens, but it's possible....

Good luck with it.

D.I Reply

Thanks for the info joe.
Goodge

In my experience, most manufacturers mean "guitar pickup" level when they say "instrument" level. Since one of the most common uses for a DI is to send a bass to the PA, it wouldn't make sense otherwise. The basic point of the DI is impedance matching - taking the HiZ guitar signal and sending a loZ signal to the board. My guess is that you have one or both pads engaged. Turn the preamps on the board up to about mic level and see if changing the pads gives you a signal you can hear.

Also, I'm not sure what you are trying to do with the DI. The purpose of the DI is to send the naked unamped guitar sound directly to the board. You can use the Thru jack to send the signal to the Marshall as well and mic that and record it simultaneously. But they are two separate and different types of signals. The advantage of having the naked signal is that you can reamp it or modify it with plugins. (You can do this with any signal, of course, but a lot of people like the effect of starting with the naked guitar signal.) Is that what you are trying to do?

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Ive noticed when a guitarist is on stage say at a live gig the electric guitar is D.I'd when entering the amp.. and i presumed this was because it sounds better i.e a fuller sound or signal and less electrical interfearence and a greater signal is sent further is this correct??. Should this be applied when in a studio situation and if so what would be the best way to do it given my D.I model art, passive ETC. I have just tried electric guitar into my D,I then into my desk and then thru signal from d.i into marshell amp recorded through a sure dynamic so now i ahve both signal one amped and one d.i naked signal in theory this should work but the d.i signal is quite low even with gain up...up...up. Probably because cheep d.i box???.
Also would this d.i in theory work using the same metod of signal split (i.e one naked signal and one amped and then recorded) with a bass guitar and synth/keys.
Thanks

I'm going to take a wild guess that your passive DI is really an Active DI. I don't think that passive DI's have as many options as you're describing.
If it's an active DI then you need one of two things. Either it needs phantom pwr. or it might work off of a 9V battery. (it might be able to do both, but there would be a switch for it)
hope this helps