What is a Direct Box for ?

[crgl]

Excuse my ignorance, but I see this DI box again and again
and don't really understand what it is used for.

Right now I record my guitar direct through a Boss GS-10 guitar effects
and amp simmulator to hard disk recording in my Alesis Fusion keyboard
which has 8 audio tracks. It is not the most natural sound but at least
neighbors don't have to complain.

Is this DI box something you can put between the guitar and the amp?
or between the amp effects amp sim and digital recording media?

Does it enhance the guitar sound ?

Thanks.

[mikemorgan]

A DI or "direct injection" box is an impedance (load) matching device used between two devices. In the case of powered DI's the box may actually bump up the incoming signal to line level. Typical uses are between bass guitar and console, from and amplifier line out to XLR lo impedance.

[cnix]

If I am recording direct, guitar, keyboard, bass, or whatever, there is usually some noise from the source. It may be very light, but over several tracks it can add up. So to keep the tracks whisper quiet, I run the instrument through the Radial JDI direct box, and all the unwanted noise is gone. I do not look for the JDI to enhance the sound of the instrument, just keep unwanted noise out.

Charlie

[Roguetitan]

DI converts unbalanced high z signal into a balanced low z signal

a 1/4" TS to male XLR transformer will do the same thing and takes up a whole lot less space than a DI box.

[ggunn]

Originally Posted by Roguetitan

DI converts unbalanced high z signal into a balanced low z signal

a 1/4" TS to male XLR transformer will do the same thing and takes up a whole lot less space than a DI box.

Some DI's have a ground lift switch that can disconnect the ground leg of the unbalanced line from the shield of the balanced line for breaking ground loops. Others have active circuitry that presents a very high impedance to the unbalanced side and boost low level signals (like from a passive acoustic guitar pickup) so that you don't have to add so much boost on the balanced side. Still others have active EQ on board.

A transformer may sub for a DI in some, but not all, applications.

[THX1136]

A DI, ideally, will not enhance the sound of whatever is plugged into it. DIs are to be invisible soundwise, but as with all things a DI will perhaps cause subtle changes to the sound - hopefully pleasant changes. It sounds as though you are using the GS-10 as a DI in your setup.

[Armistice]

And, when not being used as a recording device, a good DI box will also do service as a handy dandy doorstop. Behringer is particularly good for this.

They're also good for leaving on the floor in random places so people stub their toes on them or trip over them.

I don't know how I lived without one..

[crgl]

Originally Posted by THX1136

It sounds as though you are using the GS-10 as a DI in your setup.

The Boss GS-10 is a multi-effects unit with amps simmulation.
It only use 2 of its outputs:

1 stereo line output
1 mono amp output

It doesn't have a balanced output so I don't think it qualifies as a DI box.

This is my setting:

Guitar >>> Boss GS-10 >>> Digital Recorder in my Alesis Fusion Keyboard

I wanted to know what is the usefulness of the DI Box in a guitar setting.

[ggunn]

Originally Posted by crgl

I wanted to know what is the usefulness of the DI Box in a guitar setting.

With electric guitar, not much, IMO. The amp and speaker(s) play so much of a part in the sound that mics are the way to go (IMO again) to get the signal into recording and performance systems. For acoustic guitar, keyboards and (maybe) bass, they are very useful.

[Roguetitan]

Originally Posted by ggunn

A transformer will sub for a DI in most applications, but not all, applications.

Here gunn fixed it for ya

[ggunn]

Originally Posted by Roguetitan

Here gunn fixed it for ya

???

I posted:
A transformer will sub for a DI in most, but not all, applications.

You posted:
A transformer will sub for a DI in most applications, but not all, applications.

That's not correct. What I posted was correct, though it was a little stilted.

I could remove all the commas:
A transformer will sub for a DI in most but not all applications.

Or maybe use a set of parentheses:
A transformer will sub for a DI in most (but not all) applications.

But what I really meant to convey was:
A transformer will not sub for a DI in all applications. ;^)

[Roguetitan]

Originally Posted by ggunn

???

I posted:
A transformer will sub for a DI in most, but not all, applications.

You posted:
A transformer will sub for a DI in most applications, but not all, applications.

That's not correct. What I posted was correct, though it was a little stilted.

I could remove all the commas:
A transformer will sub for a DI in most but not all applications.

Or maybe use a set of parentheses:
A transformer will sub for a DI in most (but not all) applications.

But what I really meant to convey was:
A transformer will not sub for a DI in all applications. ;^)

no what I said is...
"DI converts unbalanced high z signal into a balanced low z signal

a 1/4" TS to male XLR transformer will do the same thing and takes up a whole lot less space than a DI box".

A DI Box transforms an unbalanced high Z signal to a balanced low z signal signal an inline transformer does exactly the same thing and most people use one or the other mostly for that purpose.
So what part of what I said is wrong?

[ggunn]

Originally Posted by Roguetitan

no what I said is...
"DI converts unbalanced high z signal into a balanced low z signal

a 1/4" TS to male XLR transformer will do the same thing and takes up a whole lot less space than a DI box".

A DI Box transforms an unbalanced high Z signal to a balanced low z signal signal an inline transformer does exactly the same thing and most people use one or the other mostly for that purpose.
So what part of what I said is wrong?

Sorry, I thought you were correcting my grammar. ;^)

Certainly, a transformer will do the same thing as a DI box as long as all you want to do is convert Hi-Z to Low-Z; open up a passive DI box, and you'll find a transformer just like the ones in the inline case. However, it will not split your signal if you want to send to an onstage amp as well as into the snake. It won't allow you to lift the ground on the balanced side if your connection results in a ground loop. It won't boost the signal from a low output passive acoustic guitar pickup like an active DI will.

I have a handful of transformers and some DI's as well; sometimes an inline transformer will do the job I need done, sometimes it won't. I use the right tool for the job; space, either onstage or in my gig case, isn't really a consideration.

[Slowrider]

I plug guitars, basses, tape decks, RtRs, mics, everything directly into the Firepod.

[stevieb]

Originally Posted by ggunn

With electric guitar, not much, IMO. The amp and speaker(s) play so much of a part in the sound that mics are the way to go (IMO again) to get the signal into recording and performance systems. For acoustic guitar, keyboards and (maybe) bass, they are very useful.

Now you know, I respectfully disagree with part of that.

YES to mic'ing your amp.
And YES to keys and bass.

But NO, I don't agree about using DI for acoustic guitar. An acoustic's body is it's "amp." Using a pickup bypasses so much of the "tone" the body gives the guitar- and although that applies to some pups more than others (the Fishman- yes, Fishman- piezo I installed on my Martin has almost no tone, compared to the guitar's body) they all basically suck, in comparison to a well-mic'ed acoustic. But, my GOD, ALL of my acoustics have such different voices- the cut-thru-the-mix quality of my Martin D-16, the mellow-cedar-top Seagull, the Wow-where-did-all-those-over-and-undertones-COME-from? Arbor 12-string (Yes, Arbor! That 12 has more interesting o-and-u-tones than any other 12 I have ever heard), the thin-and-tite Harmony Tenor... I just can not IMAGINE choking them thru a pickup.

Now, for the above, I am assuming we are talking about recording. For live sound, where the space or room can pretty well F- up all your well-intentioned attention to tone, I think acoustic pickups and DI boxes- on electrics, too- are the way to go, so you can concentrate on the performance and not worry about staying close enough to the mic, having one more piece in the sound chain from your electric guitar/amp, etc.

JMHO...

[Diverdown]

Ok
Im gonna jump in and ask some perhaps obvious questions.
In my situation I record thru a tapco usb interface that has instrument and line level selection options Would this be a built in DI?

secondly when playing a passive pickuped instrument plugged into my Behringer eurorack mixer would a DI improve the quality of this connection ?
The Mixer has xlr and balanced or unbalanced trs connections for inputs so Is an impedance matchingdevice nessesary or benificial?
Thanks heaps
P

[Wireneck]

I wanted to know what is the usefulness of the DI Box in a guitar setting.

I browsed through the responses quickly so if I missed it I am sorry. I was surprised that no one mentioned Re-amping. I do some of the tracking for my band but it is typically mixed by a pro-engineer in a pro studio. I always have a direct track running with my guitar tracks. This way if a tone doesn't work out, we just re-amp it in the studio and find something that does. This would be Impossible (to my knowledge) without having the direct tracks taken off the direct box.

[Roguetitan]

Originally Posted by Diverdown

Ok
Im gonna jump in and ask some perhaps obvious questions.
In my situation I record thru a tapco usb interface that has instrument and line level selection options Would this be a built in DI?

No one is a balanced Microphone input one is an unbalanced input for bass guitar instrument.but the High Z input is not being converted into a low Z signal if that is what you were wondering, the only way to convert the signal is to convert it with a transformer or a Passive or active DI box.
the mixer should also have a TRS input for instruments like keyboards which is also a balanced input.

secondly when playing a passive pickuped instrument plugged into my Behringer eurorack mixer would a DI improve the quality of this connection ?

Nope, in fact in some instances could make it worse.

The Mixer has xlr and balanced or unbalanced trs connections for inputs so Is an impedance matching device nessesary or benificial?
Thanks heaps
P

Di Has more to do with improving signal strength than it does to eliminate line interference noises which also depends on how long of a span of cable you are needing to use. any instrument cable longer than 20' should be converted to a balanced/low impedance signal.
with High Z signals anything longer than 20' the signal starts to diminish.
in a recording situation i seriously doubt you will have that problem.
the biggest problem you will have to contend with is line noises coming from other electrical currents being supplied to lights or other appliances.
the biggest noise problem I have to deal with in the studio is the line noise emitted from fluorescent lighting however when the lights are turned off the noise stops.

[Roguetitan]

Originally Posted by Wireneck

I browsed through the responses quickly so if I missed it I am sorry. I was surprised that no one mentioned Re-amping. I do some of the tracking for my band but it is typically mixed by a pro-engineer in a pro studio. I always have a direct track running with my guitar tracks. This way if a tone doesn't work out, we just re-amp it in the studio and find something that does. This would be Impossible (to my knowledge) without having the direct tracks taken off the direct box.

I think the OP was wondering more about soud quality of Balanced signal over un balanced more than he was reamping the signal through a DI thus that is probably why that was not discussed.

[ggunn]

Originally Posted by stevieb

Now you know, I respectfully disagree with part of that.

YES to mic'ing your amp.
And YES to keys and bass.

But NO, I don't agree about using DI for acoustic guitar. An acoustic's body is it's "amp." Using a pickup bypasses so much of the "tone" the body gives the guitar- and although that applies to some pups more than others (the Fishman- yes, Fishman- piezo I installed on my Martin has almost no tone, compared to the guitar's body) they all basically suck, in comparison to a well-mic'ed acoustic. But, my GOD, ALL of my acoustics have such different voices- the cut-thru-the-mix quality of my Martin D-16, the mellow-cedar-top Seagull, the Wow-where-did-all-those-over-and-undertones-COME-from? Arbor 12-string (Yes, Arbor! That 12 has more interesting o-and-u-tones than any other 12 I have ever heard), the thin-and-tite Harmony Tenor... I just can not IMAGINE choking them thru a pickup.

Now, for the above, I am assuming we are talking about recording. For live sound, where the space or room can pretty well F- up all your well-intentioned attention to tone, I think acoustic pickups and DI boxes- on electrics, too- are the way to go, so you can concentrate on the performance and not worry about staying close enough to the mic, having one more piece in the sound chain from your electric guitar/amp, etc.

JMHO...

I was indeed talking about live applications. For recording acoustic guitar, mics are the way to go, but unless you are in a very quiet group, micing acoustic guitar in a live performance usually does not work well if at all. Generally, DI's have much more use in live apps than in recording, IMO. There's not much point in driving short cables with a DI when you can just turn up the gain/trim on the board and use the Hi-Z inputs. There are some boards whose Hi-Z inputs are line only (they can't be trimmed up to instrument level), so in that case a DI would enable a Hi-Z instrument output to get more channel gain, but I don't think that's a very common situation.