This pair of F-4 Clone Boards use the same circuit as the First Watt F-4 model.
It sounds very good, and is extremely versatile, as each channel can be used separately, or a stereo amp can be run balanced for high power. The Amp has no voltage gain so works best when paired with an active preamp that has reasonable gain. Populate these boards with your own components, then add your own power supply, chassis and heat sinks to complete the amplifier. These generously sized, high quality boards spread the six output MOSFETS for efficient cooling. The mounting hole spacing is the same as all other diyAudio Version 2 boards.
Please see the F4 thread in the store support forum for any questions you might have and a definitive list of relevant links and resources.