Something a little different that I put together:
It started out as a mod to the Urei 1620LE and became a new circuit in the original chassis. It uses (4x) LME49713 Metal Can, which is perhaps the best audio opamp in existence and one of the newest. I experimented with discrete designs but vastly prefer the sound of this circuit.
I've got it running at 40dB gain, which is very hot but these opamps can keep up easily and I like the 'responsiveness' of the sound. Probably not for novices though for the sake of safety, and not for everyone regardless. Then again, Pioneer mixers aren't for everybody either