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The difference between 'Level' and 'gain' in a preamp.

Discussion in 'Preamps & Processing' started by recoiled_stance, Sep 13, 2006.

  1. I know that this might be a piece of cake for most of you pros out there but this is something that always keeps me wondering whenever i set the output volume of a preamp. My preamp has a gain and a level for each mic channel. what is the difference? how should i go about setting each of them cause it seems they are doing the same thing. I am sure I missing out something
    thanks for your attention
    this forum rocks!
  2. ghellquist

    ghellquist Guest

    Try setting the level real low. This will control how much is passed on the the output of the pre.

    Now turn gain fully up. This controls how much the input is amplified.

    With these settings the middle ground inside the mic pre is driven very hard creating distortion - you make like the distortion or not but that is the reason why there are two knobs.

    Many preamps has only one knob, meaning that you cannot control the distortion. Often these are made to not modify the sound, simply amplify it. Different tools for different applications.

  3. Nirvalica

    Nirvalica Guest

    Im guessing the gain actually adjusts the amplification of the signal and the level adjusts the volume of the output (so it can only attenuate the sound, not raise it at all)
  4. Ah yes now i understand. The preamp i am using has a tube in it to drive the amplification of the signal. so f i increase the gain I also increase how much tube "involvement" or "distortion " there is in the signal. thanks for enlightening me.
    thanks alot guys
  5. TeddyG

    TeddyG Well-Known Member

    Jan 20, 2005
    They are both level or gain controls - same thing(For our purposes) - whether actually amplifying or attenuating.

    The important thing is which is the "input" level/gain and which is the "output" gain/level control.

    You've got it! The first "in line" is the gain that controls how much the mic, initially, puts through the rest of the preamp circuitry. Particularly important if the pre has "other features" like EQ, compression, etc. Use of these things varies the level "through" the rest of the circuitry, right up to the "output" gain control. So the "output" level control is, mostly, to "compensate" for these changes or "differences" after the pre output to the "next" input.

    What you'd LIKE to have is a meter on the input and a meter on the output(Some do, most don't.), so you could adjust the incoming mic gain to be what you want - preferably being able to listen, too, while you adjust, but, generally, you want a nice high input level - mics are different in how much THEY put out - so you don't(Later in the chain) bring-up the "niose floor" with any needed output level increases and so you "input" no more level than you want(So you get no distortion, unless you want it.) to the rest of the pre circuitry. Anyway, at the end of doing everything you need to do in the pre, make the "final" "output" level adjustment, just prior to going to your computer, tape machine, whatever, so it is neither too low or too high and there you go.

    Like I said, "you got it!"(So why did I write this?)......


    Teddy G.
  6. Cucco

    Cucco Distinguished Member

    Mar 8, 2004
    Fredericksburg, VA
    What kind of pre is it (make and model).

    As you mention, a tube pre will have an input and output gain stage. The input will determine how much the tube stage will be driven by the input. So, if you want a heavily distorted sound, turn the input up and the output down.

    Some newer tube pres which aren't really tube stage pres have this control, but there's really not much of a difference between the input and output gain.

    On mixers, the gain and the level are obviously different though, but we aren't discussing that...


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