postamp

[question444]

newbie here with question about preamps.

from what i've learned (might be wrong), you want a preamp to give you a lot of gain while not adding a lot of noise. typically, the greater this ratio, the better/more expensive the preamp. Well, why can't one simply record the signal without any preamp, and then process the audio and amplify it after-the-fact with some supercheap wav editor? i'm pretty sure this is a bad idea, i just want to know why. thanks.

 

[mshilarious]

newbie here with question about preamps.

from what i've learned (might be wrong), you want a preamp to give you a lot of gain while not adding a lot of noise. typically, the greater this ratio, the better/more expensive the preamp. Well, why can't one simply record the signal without any preamp, and then process the audio and amplify it after-the-fact with some supercheap wav editor? i'm pretty sure this is a bad idea, i just want to know why. thanks.

Because the input noise of your converter will be higher than the input noise of the preamp. Most converters you'll find have noise at about -100dBV, which is around 25dB noisier than a decent preamp. So when you normalize that signal digitally, your signal-to-noise ratio is still 25dB worse than if you'd used the preamp first. A converter could be designed to get around that, but then it would be a converter/preamp, not just a converter.

Then there are features provided by mic preamps that aren't (usually) included with converters, like phantom power, low cuts, DI inputs, variable input impedance, etc.