Even after you've found your microphone, amplifier, and effects you still might be searching for a further refinement of your sound. Another avenue you can explore for this purpose is to alter one or more of the pieces of equipment you're currently using.

As far as your harmonica is concerned, options include retuning your reed plates or even replacing them with plates of an entirely different scale. Hohner makes a series of harmonicas known as 532/20 Blues Harp (MS) where combs, reed plates, and covers can be easily interchanged (the MS stands for “Modular System”), allowing you to easily customize your harp. Lee Oskar harmonicas are also designed to have parts replaced or interchanged.

Regarding your amplifier, the easiest modification and the one most likely to make a big difference in your sound is to replace the speaker. The speaker is the voice of your amp, and different brands and models of speakers have varying sound qualities. Some speaker manufacturers, such as Jensen, offer a “tone chart” that describes the differences in sound between their various speakers.

It's even possible to customize some microphones. The popular Green Bullet mics use microphone elements to pick up the sound. Different microphone elements have different sound qualities, and they can be inter-changed inside the Shure 520 Bullet shell.