Mosfet Amplifier 100W Example Schematic: AB class Principle Diagram

The Following Schematic is an Example about Easy Implementation of Mosfet Power Amplifier.
Power Supply is not regulated.
AB class operating.
100W could be obtained in 8ohm load.
Mosfet 2SK1058 2SJ162.Mosfet Amplifier Example Schematic

Mosfet Amplifier Schematic Example

Dowload PDF schematic document:

Mosfet Amplifier Example Schematic

QUAD 405 Vintage Current Dumping Amplifier 100W My DIY Project

This is my "remake" of first, legendary, Current Dumping Amplifier : QUAD 405.
This is one mix, my personal mix, of  his varius  release, Quad 405 I , Quad 405 II etc.

My DiY Amplifier QUAD 405

I made a stereo version with prototipe in year 2007.
Replacement components:

IC1: TLE2071 OpAmp
TR9-TR10: MJ15003


You can download pdf format below.

Electric Scheme: 

My personal Quad 405 DIY schematic diagram

PCB Layers:

My Quad 405 layout

Quad 405 components placement

Dowload PDF schematic of my project Quad 405 :

Quad 405 schematic EspritAudio

Download PDF PCB plane of my project Quad 405:

Quad 405 PCB Layout PDF

YAMAHA A-1 AMPLIFIER NATURAL SOUND DIRECT DC, FROM 70's WITH LOOK Pt.II

Pt.II

No Fault!!! 

Every component is OK, power BJT are OK!!

So I put new main chord and give power.

Both channel have some volts of offset in their output and the idle current is too low.

So, following the Service Manual I can set the correct value of bias and offset trimmers.

Next step is to change the DISC lamp

VR1-VR2: offset voltage setting trimmer

Yamaha A-1