This is one piece of bare PCB of a 80W current dumping amplifier reference to the legendary Quad 405 MK2 amplifier. While Quad 405 is a already very successful amplifier, the MK2 version has reached the high-end level in solid state amplifier. 

The MK2 boards are highly sought by diyers and finally we manage to sell them in our shop !

In Quad 405 MK2, there are two output transistors SOA protection circuits called N1 and N2. During the old days these are important when high output transistors were expensive and not as robust as nowadays solid state devices. For the sake of sonic performance, these SOA circuits can be removed, so in our boards, the two SOA circuits are optional. Users can based on the information in internet to build their N1 and N2 to wire to the appropriate position, or using wire  jumpers to bypass them as we do in our boards.

This listing is for one piece of board, which is to be used for one audio channel. For stereo application, two pieces are needed.

We provide schematic and part list to buyers by EMAIL.

PCB thickness : 1.6mm.

PCB dimension : 120mm x 82mm.

A detail account of the current dumping technology can be found here :


We do air shipping worldwide at US$5.00. We welcome combine shipping.