Page 3 of 36
Bare amplifier tests ................................................................................................... 26
Amplifier plus speaker tests ...................................................................................... 26
Amplifier plus speaker plus source tests ................................................................... 27
Final Assembly ............................................................................................................. 27
In Case of Trouble ........................................................................................................ 27
About the Design .......................................................................................................... 28
Power Supply Theory of Operation .......................................................................... 28
Amplifier Board Theory of Operation ...................................................................... 32
Table of Figures
Figure 1-Empty the power supply components into a soup bowl ....................................... 6
Figure 2-Silk screen shows power supply component locations ........................................ 7
Figure 3-Pin 1 of the opto-isolator is indicated by the dot and the ridge in the package ... 9
Figure 4-Although more subtle, notice that the Q4 has a square side and a round side ..... 9
Figure 5-Installing the mounting brackets on the power supply PCB .............................. 10
Figure 6-Grounding arrangement for speaker common connections on the SCA-80 ...... 16
Figure 7-Component locations for the stereo amplifier module ....................................... 17
Figure 8-Anode is the longer of the two leads .................................................................. 19
Figure 9-Assembling the PCB to the heatsink .................................................................. 20
Figure 10-Assembled amplifier on main heatsink ............................................................ 21
Figure 11-Assembled PCB with both heatsinks attached ................................................. 25
Figure 12-Power supply snippet ....................................................................................... 29
Figure 13-DC Good Detector snippet ............................................................................... 30
Figure 14-AC Detect snippet ............................................................................................ 31
Figure 15-Power Supply Schematic.................................................................................. 34
Figure 16-Page 1 of Amplifier Board Schematic ............................................................. 35
Figure 17-Page 2 of amplifier board schematic ................................................................ 36
