Basic Mic Pre Question

[Echo North]

This maybe a very stupid question...so I apologize in advance.

Why to gain knobs on mic pres go into the negative as you increase the gain?

Example - On my PM1000, +4 in no gain and -60 is full gain.

Can someone explain? Why is louder negative.

Thanks,

Mike

 

[skipwave]

The numbering reflects the level of the signal you are putting into it. As Kubi said, a lower input level requires more amplification.

Note that this only really makes sense with a pre that also has an output level pot or attenuator. The ideal gain staging from a noise performance perspective (sweeping generalization) is to always set the amplification to the most possible before clipping occurs, then attenuate the signal to the desired level for the next stage, a compressor, recorder, a/d converter, etc. If you notice many old pres, altec/rca/langevin/telefunken, were fixed gain and the lineamps meant to follow them always had a volume pot on the input. You can start to visualize how that gain staging worked. See some posts from NYDave and PRR about how it was done in the good ol' days.

Sorry for the long post, but I have only begun to understand how this stuff has evolved and where the confusion arises since I started reading all these wonderful posts from the knowledgeable folks around here.

 

[amorris]

audio companies like to take a standard, like -60 gain to +4 CW labeling on a lot of pres, and do the opposite. like if labeling the board with a picture of a shelf filter curve would mean that pressing the button would accuate that type of filter, while other boards pressing the buton would turn off the filter. that's why i always do a dry run any gear so i can get my head around their labeling. i dont know if they think they are tricky, or there is a question of copying other boards or most probably the designers dont really have a grasp of what is out there and guess. the silly labeling is usually on obscure gear.