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Will changing gain affect frequency response?

NOT talking about increasing the volume at the listening position by turning the volume up...

Rather, with volume kept more or less constant at the listening position, is there some technical reason for things sounding a bit brighter when the pre-amp's gain setting is increased from -10 db to 0 db (again, volume adjusted downward, accordingly) OR is it my imagination?

Think I've encountered this with my pre-amp and most recently by altering the gain setting on my phono pre-amp.  Increasing the gain by moving the jumper to the highest position seems like it opened up the sound from the Grado cart I run.  

Hence the question...will changing gain affect frequency response? 

Thanks in advance.


128x128ghosthouse

Showing 3 responses by erik_squires

erik_squires
15,861 posts
 
In addition to the famous Fltetcher-Munson loudness curves, you don't talk about whether you are running a tube preamp or not.

Tube preamps are sometimes quite sensitive to this, and it has to do with the impedance changing as the resistance in the volume changes. The better tube preamps have buffer stages or volume control configurations that prevent this, but not all.

Best,


Erik
erik_squires
15,861 posts
 
Right,  I wouldn't call F-M curves "psycho-acoustic" as your knowledge or lack of it has no bearing on the perception. It's more of an ear-sensitivity issue. 

If you remember equipment with a  "loudness" switch, or dial, they were meant to compensate for this known effect, and some speakers are deliberately tweaked along those lines to make it seem like you hear more detail at lower volumes.  Well, you DO hear more detail, but it also means at higher volumes you get exaggerated treble and/or bass. :)

Best,


Erik
erik_squires
15,861 posts
 
Well, I'm in no way arguing F-M. Of course, they are old, and may need updating, but the principle has been around and used for a long time. :)

Best,

Erik
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