My first 5 was a cheap Washburn fretted 5, passive with EMG selects. I moved the neck and bridge each out 1/2", and took/tore the fingerboard out, and replace it with a nice piece of bubinga, shaped to 12" radius. I put in EMG jazz pickups and a preamp I built on the neck pickup and put in an EMG mid boost on the bridge pickup. Eventually I made a new body of some beautiful mahogony. It turned out to be the best 5 string I've ever played, and I've not had GAS for another.
I also agree that MWAH is a factor of a properly set up bass (proper relief and string height) and the way you play. Dig in a little, and there's the mwah, especially on the higher strings. I use Labella nylon tape wounds, and my Defthane finished (a very hard bartop polyurethane) bubinga board has held up well. I can't imagine an ebony board would sound any different.
A friend of mine gave me a worn out, mid 70's all maple Precision neck. It was quite worn from roundwound strings, but it didn't take much to smooth the board out, and again, I used Defthane to finish the board. I used Fender nylon filament wound strings. I put the neck on an aftermarket P body, put in a pair of older Duncan active P/J pickups and a preamp. That was a great bass, for a 4 string. I gave it back to the friend as a birthday present after having it around for a few years. The maple was not an issue. Those Fender strings sounded like roundwounds, but were easy on the neck. They sounded great the day I put them on, and kept their tone over years of use. It had plenty of sustain and incredible tone.
