This is a high quality amplifier with LM4780 circuit from Texas Instruments. The whole construction does not hide any intrigue, and therefore it is suitable for beginners in the field of electronics. Datasheet can be viewed here: http://www.alldatasheet.com/datasheet-pdf/pdf/838824/TI1/LM4780.html
The LM4780 circuit contains two precision amplifiers, each with an honest power of 60W to an 8 ohm speaker. In the catalog they show the parallel connection of these two internal amplifiers and I use it here. This connection is more advantageous than the „bridge“ connection, because the amplifier can work with a lower impedance of up to 4 ohms. This module contains only one channel, so when designing a 2.0 amplifier, you have to build two of these modules. An external power filter must also be connected to the amplifier, as there are only two small electrolytic capacitors on the board! The entire structure is powered by a symmetrical + -35V source. When building two channels and a common source, it is necessary that the transformer has a power of at least 300W. The LM4780 MUST have a heatsink! Especially pay attention to the polarity of the capacitor C9, it may seem reversed, but it is on purpose. The power paths on the PCB must be tinned, because the housing is relatively small and wider paths will not fit there.
Printed circuit board:
Placement plan and PCB are at 1:1 600 dpi (How to print a PCB design can be found in the post How to print PCB design). Real size PCB is 71,8 x 45,0 mm.