2 x Dual = 1 x Quad

This is a sort of sequel to the article ‘2 × single = 1 × dual’. In this case, two dual opamps are combined to make one new quad opamp. This allows many possible variations, and again it allows two completely different types of dual-opamps to be used.It is very easy to replace a quad opamp if you use the printed circuit board shown here. The schematic diagram shows the interconnections between the two dual opamps and the pin locations of the quad opamp.