Do I need a DI box?

[gbeam]

Given a soundcard with the following specs, do I need to use a DI box, or can I simply plug into the card directly?

Input LEVEL : -10dBV Unbalanced, -10dBV Nominal, +3.0dBV Max
Input Impedance : 10K ohm

 

[cusebassman]

...

Okay, this is just your typical PCI soundcard on your computer, correct?

Secondly, what are you trying plug into it?

 

[gbeam]

...

Okay, this is just your typical PCI soundcard on your computer, correct?

Secondly, what are you trying plug into it?

Card is an Audiotrak Maya 44 (1/4" stereo inputs x 2), and I'm plugging in a guitar. Just wondering if I really need to use a DI box as the impedance of the card *seems* to be matched to the output of the guitar, but my understanding of this is very limited.

 

[danny.guitar]

Have you tried it? I don't think you'll damage anything just by hooking your guitar straight into the sound card. A DI might help though so you can control gain more easily.

 

[mshilarious]

You need a DI, the input impedance is far too low for guitar. You could stick a stompbox in between as a buffer if you wanted.

You might also need some gain (especially if you use a passive DI or an active DI with an internal pad), so if these inputs are strictly line-level, that could be a problem.

 

[MessianicDreams]

You need a DI, the input impedance is far too low for guitar.

Exactly. You'd need an impedance of roughly 10x for there to be a proper impedance match.

Also you need to look at whether the input is stereo or balanced...

 

[cusebassman]

I don't know much about impedances, unfortunately - I know more along the lines of line-level vs. instrument level, and what gets you from one to the other.

So, the card you specified resulted in this at the end of a google search:

http://www.soundonsound.com/sos/aug04/articles/mayam44mkii.htm

This card has 4 line inputs. Line level is significantly higher than that of a guitar's output. You can try to run the guitar direct in and crank the gain, but it is likely to be extremely noisy.

The proper way to go about doing this is to get a preamp and a DI box, or a preamp that has DI built in.

The Direct Input on the M-Audio DMP-3 is actually halfway decent, and the preamps are very good.

Now, I don't know how recently you bought this card, but if it is still new, I would recommend returning it and just buying an outboard interface. You can find Presonus Firebox's on ebay for around 200 dollars used, and those have a decent DI built in. They do require firewire, but if you don't have any firewire jacks on your computer, you can buy a firewire card for around 30 dollars. And since you are obviously adept at installing PCI cards, this would be no problem.

I only recommend swapping for the Firebox because spending the money on something like the DMP-3, combined with what you spent on the audio card, would put you over the cost of the Firebox anyway, and the Firebox works pretty damn well for the cost, and should come with a copy of Cubase LE as well.

But, its up to you - let us know where you are going to go from here, and we'll help ya along the way!

- Glen

 

[cusebassman]

Also you need to look at whether the input is stereo or balanced...

The inputs are stereo, un-balanced (jack #1 corresponds to inputs 1 and 2 in the software control panel).

So, on top of getting output from the DI, you will have to get a splitter for the card's input to allow you to input something into only channel 1 or 2. Not terribly expensive, just another piece of the puzzle.

 

[gbeam]

Have you tried it? I don't think you'll damage anything just by hooking your guitar straight into the sound card. A DI might help though so you can control gain more easily.

I've gone directly in, and I've gone in using a DI box - I personally couldn't hear a difference.

Everything I've read about DI boxes seems to indicate they should be used to bridge impedance and to convert from unbalanced to balanced, but seeing as how my soundcard's input is unbalanced and the impedance is the same as the guitar, I don't see what I would gain from using one in this particular case.

 

[cusebassman]

I've gone directly in, and I've gone in using a DI box - I personally couldn't hear a difference.

Everything I've read about DI boxes seems to indicate they should be used to bridge impedance and to convert from unbalanced to balanced, but seeing as how my soundcard's input is unbalanced and the impedance is the same as the guitar, I don't see what I would gain from using one in this particular case.

If you don't hear the difference, then I would suppose it doesn't matter. It isn't "technically" the right way to go about running in, but if you're happy with it, that's all that matters.

If you plan on sending this out to be professionally mixed and pressed for release, I'd say upgrade a bit, but otherwise, I wouldn't worry about it.

Just realise that if you decide you want to record vocals or anything else with a mic, that you will endup having to buy a preamp for the mic - you definitely can't plug one directly into that soundcard, as far as I can tell.

 

[gbeam]

You need a DI, the input impedance is far too low for guitar. You could stick a stompbox in between as a buffer if you wanted.

I read that a guitar had an impedance around 10 kilo ohms, which is what the card appears to be as well. I guess that's incorrect?

 

[gbeam]

The inputs are stereo, un-balanced (jack #1 corresponds to inputs 1 and 2 in the software control panel).

So, on top of getting output from the DI, you will have to get a splitter for the card's input to allow you to input something into only channel 1 or 2. Not terribly expensive, just another piece of the puzzle.

Not an issue as these days, I only record 1 track at a time with this card.

 

[cusebassman]

Not an issue as these days, I only record 1 track at a time with this card.

Im not worried about you needing to use both channels - but as far as I know, plugging that mono cable into a stereo jack means that both channels 1 and 2 are stealing half the signal from that cable, so you aren't getting the full strength - and when we're talking about a guitar-level signal, that's quite the difference.

But as you said, its been working for ya, so whatever.

 

[gbeam]

If you don't hear the difference, then I would suppose it doesn't matter. It isn't "technically" the right way to go about running in, but if you're happy with it, that's all that matters.

If you plan on sending this out to be professionally mixed and pressed for release, I'd say upgrade a bit, but otherwise, I wouldn't worry about it.

Just realise that if you decide you want to record vocals or anything else with a mic, that you will endup having to buy a preamp for the mic - you definitely can't plug one directly into that soundcard, as far as I can tell.

The card is actually an older model than the MK II (I've had it for several years), and you can plug a mic directly into it (with an XLR to 1/4" adaptor), although I wouldn't as I found the onboard pre-amp to be terribly noisy.

 

[cusebassman]

The card is actually an older model than the MK II (I've had it for several years), and you can plug a mic directly into it (with an XLR to 1/4" adaptor), although I wouldn't as I found the onboard pre-amp to be terribly noisy.

Ah, I thought I read that somewhere about the USB model (didn't realise it was also on thr PCI version) - that you could run a balanced mic in as well... what an odd feature bundled into the same jack with what is otherwise two separate channels - not confusing at all

 

[gbeam]

Im not worried about you needing to use both channels - but as far as I know, plugging that mono cable into a stereo jack means that both channels 1 and 2 are stealing half the signal from that cable, so you aren't getting the full strength - and when we're talking about a guitar-level signal, that's quite the difference.

But as you said, its been working for ya, so whatever.

Now that's something I never considered! Mind you, the levels (either direct or with a DI box) have always been plenty loud. I've always had to turn the software mixer level down to about 50% so as to not be in the red when playing hard.

 

[gbeam]

Ah, I thought I read that somewhere about the USB model (didn't realise it was also on thr PCI version) - that you could run a balanced mic in as well... what an odd feature bundled into the same jack with what is otherwise two separate channels - not confusing at all

Did I mention the (crap) pre-amp is only available on input 1 (channels 1+2)

 

[cusebassman]

Did I mention the (crap) pre-amp is only available on input 1 (channels 1+2)

In relation to my thread in the mic forum, now my head hurts for two reasons

 

[DAS19]

If you dont hear a difference then theres no point in even posting this cuase I guess you answered your own question. Its weird you arent getting better results with a di. Is it a tube di? I would try a tube but if its still no better then just use whatever you feel comfortable with man.

 

[gbeam]

If you dont hear a difference then theres no point in even posting this cuase I guess you answered your own question. Its weird you arent getting better results with a di. Is it a tube di? I would try a tube but if its still no better then just use whatever you feel comfortable with man.

It's a passive DI, and the fact I'm not hearing a difference is why I'm asking