Hey ya’ll,

I’m hoping someone can help me understand this in a simple practical way. On my Emu interface the gain control knob in addition to the normal markings has two wider markings specifically for “unity gain”. But these markings don’t give me a good level to record with using either kind of cable….. Is it supposed to? I don’t get how I‘m supposed to use this. I have read a little about gain staging and I know that unity gain is supposed to help get a cleaner signal - beyond that my eyes glaze over….. Is there something I should be doing with it that I’m missing by ignoring it and just setting the level to get a decent signal?

From my manual: The preamp level controls set the input gain from 0dB
to +65dB. The wide mark indicates the 0dB/unity
setting when using unbalanced input cables. The 0dB
mark indicates unity gain when using balanced input cables.


Thanks so much.

Josie,

Can you give the specifics on exactly which Emu interface you're using, along with details on the DAW, ...etc?

Hey Bob,

Sure, Emu 0404 USB. I record into Realband then drag drop and do the mixing in Tracktion.

Oh, just to clarify my first post - my gain knob works fine. I just have to turn it up beyond the "unity gain" setting to get a good mic level. I'm trying to understand "unity gain" and how to use it for a better cleaner sound.....

The unity gain setting simply means that the input signal level will be unchanged;
it will neither be increased or decreased in level. There are two different types
of inputs, balanced and unbalanced, and the position on the control just happens
to be a little different for the two inputs. If you wanted unity gain, you would
just use the mark for the input type you were using.

If your input were a line level signal, you would likely want to use unity gain
which is also referenced as 0db. A line level signal is already at a level that
is appropriate for further processing. So it normally doesn't need any additional
gain.

A mic is very low level though and requires gain to bring it up to the line level
required by the next stages. That is why you need a higher setting on the level
control.

Levels need to be controlled more or less, so that they remain within reasonable
limits. If the level goes too high, distortion results. If it goes too low, one
of the later stages will need additional gain, and adding gain will add some noise.
A lot of gain is necessary with mics, and preamps are very low noise so that the mic
signal can be brought up to line level and remain clean. For that reason it's important
that the gain for a mic occurs in the input amp where it can be done with minimum noise.
So you want to adjust the input level to a point where all of the later levels can remain
at or around their own 0db level.

.

And also that Unity gain mark is going to make a lot more sense if you are using a line level input such as a keyboard. With a mic, not so much, as you have noted, we must get a lot more gain than 1 before we can use the things.

Unity gain is "what goes in is what comes out" amplitude-wise.


--Mac