100k is a little high. With a 100k full up the bass and
treble controls have very little effect.But you will get
about 12db more @ 400Hz compared to the 10k full
up. Give it a try you might like it. Once you get past 2
or 3 on the 100k it becomes a gain control more or less.
I like a 25k in there...but then I tend to run the controls
close to "flat" anyway with the mid on 8 or 9
 
I tried a 25K. Not that big of a difference. I tried a
100K audio. It works great. You have the same
midrange control up to about 3-4 and after that it
becomes a gain boost. I really like it.