[ratso]

forgive a dumb question. if i wanted to mod my headphone amp to achieve more gain
(db) output, what piece is physically being replaced? is it the opamp?

[BradJudy]

Replacing the op-amp will not (in general) change the gain.  It's likely you'd have to change the resistors used around the op-amp. 

[ratso]

thanx brad, thinking about having my amp modded and was wondering how
big a surgery this would be.. now to find someone to do it.

[boead]

Gain can be related to the impedance of the headphones and how well they are matched to the amps design and components.

What headphone amp and headphones are you talking about?

[ratso]

actually i am not using it as a headphone amp. i use my channel islands audio as a preamp to get some gain for my modded squeezebox which then goes directly into my power amps. sounds awesome but a touch more gain would be useful if possible. i have contacted CI to see what they say.