[dokebi]

I was wondering if it was possible to implement separate controls for bass, treble and balance into a meta42 and how much extra work it would require.

 

[mwach]

It is a good question.

Anyone can give some hints ???

 

[Wodgy]

There are several ways to do this. Chu Moy has a good tutorial article here, with some good solid, easy to build designs:
http://headwize2.powerpill.org/proje...=equal_prj.htm