Mic pre gain stage theory?

[kirkbross]

I'm trying to get a better grip on gain stage control. I've been just going by ear (which I know is the best way to learn) and I get a pretty good sound going through my Chandler LTD-1 pre. I'm just want a more scientific understanding of input gain and output levels... for intimate vocals, I usually have my input gain at -55db and the output barely up (on about 2 out of 10 dots).

My question is: Does one get the most "coloring" from a pre amp when [A] the is gain high (hotter) and the output low, or [B] when the gain is lower (closer to zero) and the output higher.

(Also, if there is a good article or book on understanding gain stages, I'd love to read it).

Thanks in advance-

ps- You can hear an example of what I consider intimate vocals on a song called "Blue Light" on my site (KIRK ROSS :: THE OFFICIAL WEBSITE OF KIRK ROSS). I have a Pearlman TM-1 going through the Chandler into a Distressor and then into my Digi002.

[Kronos147]

What do you hear when you turn up the input high and output low vs. the input low and output high? Is there a middle ground that is much different?

Each pre based on its topology should respond differently. Some may not like to be driven too hard.

There is one thing in general I have found, and that is I start with the output half way and move up, if it is too loud and I feel I need to turn it down past half way, I reach for the input gain then.

Geoff Tanner told me on his GTQ2 I shouldn't have to drive the output at 75% or more and to adjust the input if I got to that point, so there goes my generalism.

You have to try it all though to see what works for you.

[Dean Roddey]

My question is: Does one get the most "coloring" from a pre amp when [A] the is gain high (hotter) and the output low, or [b] when the gain is lower (closer to zero) and the output higher.

Pushing up the input and pulling down the output, generally speaking, drives the device harder. Whether that's a good thing depends on the device. But a lot of pre-amps will start to create more harmonics and often get thicker sounding as you push up the input more, beause you are pushing a hotter signal through it.

The other way (generally, I'm sure there are exceptions) tends to provide the cleanest and least colored sound.

I would kind of think that intimate vocals have as much though to do with using a nice LDC mic and letting the singer get right up on it and using a cardiod type pattern to get maximum detail, something like that. But having the gain up would probably contribute nicely, though it may not. As the old rule goes: There are no rules.

Gain staging in generally just means not introducing unwanted noise through the system, and keeping the signal up nicely above the noise. You dont' want to send the signal into a pre-amp and then pull the output down really low, then feed it into another device which you then turn up, and so on. Each time you do that, you are losing signal and gaining noise.

[Daystar]

I also have a question on the subject ...

I have Great-River Me1NV .
what are the gain setting you use usually ?
what setting gives you the right sound before clipping ? I don't want to record Too hot ...

[Dean Roddey]

There are three things involved. There's the level coming into the pre (and the gain you apply to it), the level going out, and the levels you see at your converter's inputs. The big one is the level you see at the converter inputs. You don't want to push that one because if you clip there it's going to sound nasty.

The GR has meters, so you can tell if you are pushing it too hard for input or outputs. As long as you aren't getting into the red on the meters, or the converter's meters, then the rest is just what sounds good to you and insuring that your converters are getting a good but not too hot signal. If you push the pre-amp way too hard, you'll hear it distort and clip and you should see the meters showing you this. But otherwise, you can push the input gain more and bring down the output (to get the right levels on the converters), or you can do the other way, and decide which way it sounds best for the track you are doing.

[moonpi]

Originally Posted by Daystar

I also have a question on the subject ...

I have Great-River Me1NV .
what are the gain setting you use usually ?
what setting gives you the right sound before clipping ? I don't want to record Too hot ...

The ME1NV has such a wide variety of sounds in it. If you do some experiments of input vs. output by recording the audio and comparing your waveforms, you should see that the transformer saturation of the Great River acts much like a compressor. It also adds the nicest fur this side of an over-driven 1176 or even the UA 2108 (which was, sadly, discontinued and one of the coolest sounding mic pres ever).

Really, you are going to just have to use your ears and twiddle the knobs until you find what levels work for your particular source and signal chain. I'm afraid there is no magical voodoo beyond trusting your ears and instincts.

By the way, congrats on owning the Great River! Those are such great preamps!

[Dean Roddey]

you should see that the transformer saturation of the Great River acts much like a compressor.

This is very true, and something I was quite suprised to discover that. It's quite useful when you aren't using any compression.