Difference between GAIN and LEVEL

[Bobbsy]

I was trying to avoid getting into that but ashcat is, indeed, correct.

However, for setting gain and levels in a live situation or your studio, just add and subtract. Actually, that's largely why we talk in dB. It makes the practical relationships much easier to deal with.

 

[miroslav]

Unless there were some other variable missing in a scenario like that, it simply isn't true. I.e. the dynamic contrast (ratio) between the desired content, 'background or 'softer or unwanted content at the mic, isn't changed by where the level is increased.

Well...maybe when we talk about tube preamps, then that might be the "missing variable".

If you set the gain low on a tube preamp...and raise the output level to compensate, it might not sound the same as when you raise the gain to a certain level, and then adjust the output...even if the actual numbers equal the same at the output in both scenarios.

Depends on the actual circuit and what the gain is driving inside the preamp...whereas the output level is usually post everything else. So I could see why there WOULD be a different sound in some cases with the gain up and level lower VS the other way around.

 

[ashcat_lt]

Yes, there is a difference between distorting the input and then turning it down and not distorting it and not turning it down. Which one sounds better depends on the preamp itself, and what you're shooting for.

How that will impact noise also depends on the preamp, and where it's adding its own noise. Every gain stage will amplify the noise coming into it. Some just add a static level of self-noise so that turning down the gain will degrade your S/N. Others seem to amplify their own noise so that they're overall noisier at higher gains.

This is where we need to actually experiment and learn our preamps if we really want to use their idiosyncrasies to our advantage. In general, though, most devices are intended to run at their nominal level - 0dbVU on the mixer's meter. If we're just slapping something together or working with unknown gear and just want the best chance of reasonable success, then we usually prefer to get as much of that level as close to the source as possible for noise reasons, and we try not to avoid turning it down ever, but especially not if we going to have to turn it back up.

 

[rayc]

I stepped in only to make a summary using a low common denominator.

 

[mixsit]

Well...maybe when we talk about tube preamps, then that might be the "missing variable".

If you set the gain low on a tube preamp...and raise the output level to compensate, it might not sound the same as when you raise the gain to a certain level, and then adjust the output...even if the actual numbers equal the same at the output in both scenarios.

Depends on the actual circuit and what the gain is driving inside the preamp...whereas the output level is usually post everything else. So I could see why there WOULD be a different sound in some cases with the gain up and level lower VS the other way around.

Fair enough. I mainly wanted to dial in on a different point there.

One way to compensate for reverb and background noise is to lower the gain and increase the channel fader to achieve the proper level.

.. the main question is how are gain and the channel fader different in terms of how they affect the microphone's sensitivity?

The only other variable' I can think of to effect that would be a compression or reduction of the dynamic range.