Will changing gain affect frequency response?

Thanks for the replies so far.

The tube pre-amp (2-6H30s, 1 EZ80 rectifier) is what has a -10 db option. The effect from altering the phono pre gain setting was "heard" in playback using a solid state integrated amp (no tubes involved in that chain).

I’ll check info at those links.

Take away so far, however, is there might be an objective basis for a difference in tone...not just imagination.

hahaha...okay. Started reading Rodman's link.  Didn’t know anything about the Fletcher Munson curve. So, it sounds like there is a well known linkage between volume and perceived frequency response - a psychoacoustic effect, I guess. But let me repeat, what I’m asking about is what might explain an effect on frequency response when the volume at the listening position has been adjusted down ("normalized") to compensate for the increase in gain. Is the F/M response relevant in that situation?

Psychoacoustics is the scientific study of sound perception. More specifically, it is the branch of science studying the psychological and physiological responses associated with sound (including speech and music). It can be further categorized as a branch of psychophysics.

Loudness is the characteristic of a sound that is primarily a psycho-physiological correlate of physical strength....

Hi Eric - I'm using psychoacoustic as defined above applied to the perception of loudness quantified by "phon".  Because of how we perceive sound, varying dBs are required to support a constant level of loudness across a range of frequencies.  Each F/M curve is dB (Y) as a function of frequency (X) for one level of loudness (constant phon). 

I suspect what I'm hearing (if real!) might be a function of electronics, not a function of the "hearing response" (one aspect of which the F/M curves are describing).    

Thanks, Al.  Does sound like there are few possible hardware-based explanations for what I thought I heard.  

Hello again, Erik.  Thanks for your time considering this.  I'm not arguing the F/M curves either....more a case of not sure they explain what I think I hear when gain is increased but volume reset to the original level.  

Rodman - Absolutely no need to apologize. Those Fletcher Munson curves were new to me so you added to my little store of audio knowledge. Thanks for taking the time.

Czar - Interesting analogy.  I think I get your point applied to gain settings.