J-FET input cascode class A preamp/headpjone amp + onbrd reg + protection PCB !

This is a bare PCB of a highly integrated preamplifier/ headphone amplifier. The amplifier and on-board regulator circuit is with reference to successful designs from Marantz SC series preamplifier.

Design features :

The output stage is designed to work in class A mode ( quiescent current adjustable from 20mA to 50mA). Either MOSFETs such as Renesas 2SK213/2SJ76 or BJT such as BD139/BD140 can be used as output transistors.

Due to the high operating current, the preamplifier can be used as either a preamp or a headphone amplifier.

The board has integrated high speed low noise regulator for best performance.

Output protection circuit is also included to protect the headphones( and your ears !)

Each board consists of two channel thus one board can be used for stereo application.

The schematic is shown below for reference. We provide detailed schematic, part list and construction guideline to buyers by EMAIL.