This section is about analogue circuit design, it will have a number of hints, tips, suggestions for further reading and suggestions for computer design software.
Most simulations of analogue electronics use some version of spice. An easy to use free version, that can be used on small to medium sized projects is LTSpice. It is possible to use device models from other device manufacturers within LTspice. Always view the output of any simulation tool with a careful eye, for instance some early models of the 741 opamp could produce an output of 11KV, when on +- 9v DC rails… (not possible!)
Many of the big vendors of analogue integrated circuits also have their own simulation packages, such as Analog Devices and Texas Instruments.