Here is a truly classical implementation of the diamond buffer. A headphone amplifier.
There isn’t much to be said about this topology. It’s pretty popular and is used in variety of applications. One application is buffering an opamp’s output so that it can drive low impedance high capacitance loads like a pair of headphones. Here is a schematic showing the diamond buffer as a current booster for an opamp:
The gain is set by the resistors R5 and R2. If you are using NE5534 the C6 capacitor is a must when gain below 3 is set. For more info on this read the 5534 opamp datasheet.
The buffer is biased in pure class A at about
300mA 30mA. That will give a plenty of headroom for plenty of voltage swing. To calculate the quiescent current use the following equation:
This amp will output a substantial amount of power so it must be used with care. Always switch it on with a volume pot set to minimum. It’s very easy to damage you hearing so be warned!
The PCB artwork is available for download HERE. You need two PCB’s for a stereo application.