Various types of Gainclone circuits...

1. Basic Non-Inverting circuit.
Input signal is fed into the non-inverting input of the Audio Chip. It is the most basic and popularly used configuration.
Ref: LM3886 Datasheet.

2. Inverting configuration.
Input signal is fed into the Inverting input of the Audio Chip. It is not commonly used, but audio enthusiasts who had made circuits in this configuration had reported better audio quality in terms of clarity and headroom. It also uses less number of components.
Ref: LM4780 product Datasheet.

3. Advanced Non-inverting circuit.
A few additional components are added in the basic circuit to form advanced circuit. Additional components are added to improve certain characteristics like stability, immunity to oscillations and erratic behaviors of Audio Chip.
Additional components – RIN, CIN, RB, Cf, Rf2
Ref: LM4780 product Datasheet.

4. Parallel and Bridged circuits.
Gainclones are highly flexible ICs. They can be connected in Bridged configuration (BA), Parallel configuration (PA) and in hybrid bridged-parallel configurations (BPA). Configurations can be decided based on Drive voltage and Load Impedance.
Ref: Design note by NS. An1192
External Links for PA & BPA designs:- BPA300 Gainclone, PA100 Gainclone


5. Special circuits.
Audiophiles who understand true potential of Gainclones Chips had harnessed their untapped potential by making special circuits employing buffers, DC servo control and controlled feedback. Some of the circuits are:
External Links:- My "audiophile" LM3886 approach in DIYAudio