Spice

If you're cooking a stew and it tastes bland, a little salt will often do the trick. Salt, properly used in moderation, brings out the flavor of food. It was once the most coveted of all spices, more expensive than even jewels. When a designer auditions his best efforts at a new design it may not meet his expectations–perhaps sounding a bit bland: or a little hard, rough around the edges, not enough body on instruments, too little extension on upper harmonics. The list of things to look for is long. Cooks as well as designers need a bag of tricks they can employ to take a finished product and turn it into a masterpiece. Master craftsmen of both food and audio build repertoires of useful knowledge. Having that wealth of information available for new designs is essential; rarely available in books, never taught in schools. Over the years I have worked on many projects, and here's some of the techniques to improve their musicality. Adding JFETS. One of the classic means of relieving a bright sounding amplifier of its exaggerated and often fatiguing presentation is to replace the input device from a bipolar to a JFET (or a tube). JFETS have a softer, more rounded attack signature when used in a circuit, but you have to be careful. Depending on where in the circuit, they can also lose information and over-soften the sound. Again, experience counts; rules aren't hard and fast. Increasing loop feedback. When building a power amplifier it's instructive to know there's a very tricky balance required for the overall amount of feedback. Adding gobs improves the damping factor and control of the loudspeaker. But too much and you tilt towards an edginess. This is where listening carefully and knowing the proper blend is critical. Extending low frequency response. We can't hear below 20Hz, but we certainly can feel below that frequency - and we can perceive phase problems resulting from cutoffs. If a design presented to me has less than stellar bass, and it's cutoff is 1Hz, sometimes lowering it by a factor of 10, to 0.1Hz, does the trick. There are tons more techniques developed over the years, but these are good examples of stuff you don't learn in the book-schools, but you do learn in the life-schools.