Here are some ideas that I've had about tone - - some of which ended up some other web conversations and e-mail lists.
Here's what I'm trying to achieve with my sound . . . I think that it's pretty different from what people are normally trying to do.
+ I want the *core* of the note but also a big *footprint* (read "air") - - solid fundamental with character around it.
+ I want something with lots of resonance and air. (This is why I use piezo film pickups UNDER the bridge. I get lots of wood sound. Most people use piezos for super highs and "grit" or "zing." the pickups "see" the string . . . mine see the string, but "through" the bridge and with lots of body. I don't like the mostly metallic sound that most people get from piezos.)
+ I want something which has a fair amount of attack as well - - the thud of the strings. (I get this by running a small tube compressor into one side of a Walter Woods stereo head.)
+ I also want a fair amount of dirt or harmonic distortion - - especially as I play harder. To me this becomes an expressive issue. If the bass sounds too high-fi (sterile to my ears) I think it lacks "emotion" or expression . . . both of which are paramount to me. (I get this by running a small tube pre-amp - - slightly overdriven - - into the other side of a Walter Woods stereo head.)
+ I also (and seemingly contradictorily) want clarity. I want total nuance of string and note and body without the sometimes annoying uber-zing of having too much treble. If it's "too" clear it doesn't have "oomph" . . . if it's too "oomphy" it lacks clarity. It's a hard balance for me to get.
+ For me, "midrange" is where the character and nuance and harmonic information come from.
+ I want a fairly even sound across the range of the instrument.
A lot of my thoughts about this came from when I studied upright bass. I really had to come to grips with what tone was, what I wanted. I needed a note that speaks, but that has character. Later I transferred that process and conceptualizing to electric bass (not the actual sound, but the idea of working on a sound).
It also comes down to my conception of the instrument/how I play. I view *what* I do/what my goals are as being a cross between a guitar, a bass and a 'cello (or sometimes a mini-orchestra) - - I try to cover a lot of ground in my approach to the instrument, both in improv and in writing for it.
I really want to get more of an "acoustic" sound of a non-acoustic instrument.
I have a friend (guitar player) who says that he doesn't want "clean" or "transparent" (a la most bass amp manufacturer adverts), he *wants coloration* . . . and I pretty much agree with that idea.