Do I need a mic preamp if I already have an audio interface?

In the latest issue of Computer Music Special, "Singer Songwriter Production Guide" it illustrates a mic preamp in the signal chain that leads up to an interface. The thing is, my interface has built in Phantom power which I assumed was the mic preamps. I wasn't aware I needed a separate mic preamp unless CM is giving us outdated or inaccurate info. I thought an interface with built in phantom power and a mic was all that was needed. What's the deal with mentioning the mic preamps several times in their article? They even stated their interface has phantom power, but yet use a mic preamp. So everyone with an audio interface now has to go out and buy a mic preamp?

A stand alone preamp can help w/ your sound.  Most (if not all!) built-in preamps are transformerless designs and do a good job.  If you buy an external preamp (that costs as much as your interface or more) you are likely to get several benefits.  First is greater gain.  With more gain you can back a singer off the mic, for example, and still capture a nice signal.  If you room is ok, you'll get more "air" around the voice, less proximity effect and timbre change when the vocalist moves their head, and a more even sound (volume drops x-4 for every 2x of distance) giving a natural compression.  Basically, more gain gives you more flexibility w/ placement.  

The components are usually higher grade.  Power ain't shared w/ a bunch of other components.  A bunch of little stuff that adds up.  Not night and day in the overall scheme of things, but once you develop skills and the ear it can help recording.  There is a reason the pros spend the money and it ain't just ego.  It may only be 1%, or 5% gain in precieved sound quality, but enough to warrent spending the money.  And for the less experienced there is the confidence thing.  "Well, this sound sucks but it can't be the preamp, so it must be something else, including me."  If you buy dedicated equipment, it lets you focus on other things that compromise your sound.  And as you work on that you develop your skill and your ear - even as you get older (cough, cough) you hear better.

The last thing is transformers.  To me, this is one of the things missing from digital.  Digital is clean, little noise floor and sharp-sounding.  Transformers in the picture give back some of that analog sound we (especially us older people) we associate w/ music.  It rounds out the sound we put into digital, which sounds better.  Transformer ain't cheap ($75 is low cost for a good transformer) which means they don't use them in the signal flow in  $100 a channel interfaces.  Whereas a good transformer and highquality electronic components do give me the sound I associate w/ music, since that is what was used for years making music.

The M-Audio DMp-3 and RNP are good, low cost stereo preamps w/o transformers.  The GaP and ISA One are good, low cost preamps w/ transfomers.  Cost goes up from there.  You don't need to buy one to get a good sound, but if you do and use it for a while, you are likely to like it.  Mics are likely to be more of a game changer, but once you have a couple of good ones preamps are next in line for making a difference.

@

yeah... some interfaces have nice preamps and theoretically, no other pre is needed. 

However, some of the preamps (standalone) have a unique sound or coloration which they impart that is sought after. 

So.... yes.... maybe. But only if you seek that signature sound from a specific model of preamp. 

I find preamps really help the vocals sparkle and stand out.

the interface does it automatically most of the time as long as you're plugging in a 1/4" TRS or TS instead of an XLR.  others have switches on them you have to set.  so it depends on which interface you have (tell us a make and model and we can give you more specifics).

the output of the preamp will be LINE level, so you connect that to the LINE LEVEL input of your soundcard.

MIC to PREAMP to SOUNDCARD (same thing as "audio interface")

no, preamps do not just supply power - they provide GAIN.  a MIC is a very low level output device, you have to amplify it with gain.  the preamp will bring the MIC level up to LINE level for the input of the soundcard.

how do you know if you have a nice one?  look at the price!  lol!  the cheap ones are not "good" ones, but they might work OK.  very cheap ones like the m-audio audio buddy are only as good as you pay for them (~$25 per channel for 2 channels) but it's likely your soundcard/interface already has preamps at least as good as if not better than pres like the audio buddy.

AT


Some interfaces only have preamps, not line level inputs.  I'm thinking the PreSonus FP and the Yamaha/Stienberg one.  In that case, if I understand right, the line input goes through the preamp circuitry but is padded down.  Some people claim to hear the difference, but people say lots of things.  I never noticed any degredation with my FP, but maybe that is just me, or maybe it was the fact I used the inserts most of the time.  All other things being equal, use line inputs w/ preamps.

That is what a mic preamp does - takes the small signal that comes from the mic transducer and pumps it up to line level that other electronic units can see and use.  As Mike once put it, it is just another amplifier, but w/ a specific job.

As far as good preamps - I suppose you are asking about the interface's.  The smart ass answer is to listen.  But you can read the specs to see the gain.  Roder Nichols (Steely Dan) used the cheapish DMP transformerless preamps and didn't sell less units for that reason.  Most preamps sound good - certainly good enough not to get in the way.  The Impact preamps in my TC Konnekt are good - I could hear the difference in them when I switched from presonus.  But many engineers look for a little something extra or different, a wow factor if you will.  Another thing, but related to wow, is most interfaces will only have one or two preamps w/ inserts for EQ or compressors.  If you want to add those for wow when recording, you'll be out of luck w/o inserts on your interface preamps.  W/ external preamps (even if they don't have inserts) you can chain them w/ whatever analog hardware you have cables for.

@

Excellent thoughts, IMHO, AT (and your prior post).
 
If you record at a home studio ... vs. on the road where distortion abounds and ... you might get away with no vox pre.
 
But in the studio, a dedicated Vox pre, like the $2000 Avalon or Portico Neve, will also tame hiss, hum, and Ess artifacts ... that your/my ears can instantly commend.
 
Note: We've argued fanatically about this before: In sum the verdict has been:
 
1) A vox Pre is not a do or die necessity.  You/I can record at hotel rooms with an SM-58 and a tiny sound interface and do just fine for pop recordings.
 
2) But, a colored vox for pristine artsey recordings requires a pre, condensor mic, and best signal chain.
 
3) Both 1 and 2 require a 'good' singer!
 
You decide.

+1 Spacealf ... studio channels, pitch software, comps, and the plethora of fx's can redeem almost any vox!

Hahahaha! 

Additionally: there are some/many who'd frantically exclaim that a good room with bass traps is more important than a vox-PRE ... and vice-versa!

But here's the math I discovered:

   any popular cardiod mic (including Radio Shack)
+ any cheap pro sound card ($100)
+ Super 8 hotel curtains
+ keeping the mic cardiod field away from the window a/c unit
+ passion / inspiration / sincerity
+ a quality vox of 'church-choir' level or greater
+ multi-takes
+ fx-bin fx's (limiters, comps, de-essers, pitch correction software, chorus, tools)
+ a track cleaner: like Waves x/z Noise Cleaner
+ some manual compression: aka, gain or volume envelopes
------------------------------
= pop-worthy

Other valid reasons to use a Pre:

1) You are both the lead singer and composer.  A Pre will 'optimize' this creature.
2) You don't have time to do all the math.
3) You need to de-ess at the source (which some producers prefer)
4) You are a noob singer/composer but can handle the hardware OK.

Note: I don't frantically hold to these views anymore as others have will rebuke my logic.