In the previous posts about these simple mono amplifiers, we already had a detailed look at the schematic, all the parts needed and the initial construction steps. The last post showed the mounting of all components which go directly to the metal plate and the wiring of mains and heater connections as well as the high voltage AC.
Now we will go through the remaining assembly steps. All the parts which are still missing will be soldered to terminal strips. First we have to make a foundation on which these can be attached. For this I used my famous aluminum profiles:
Now choke and output transformer get added and wired up:
Two more aluminium rails are used for this which again attach to the metal plate with bolts, long enough to keep them above the tube sockets. Extra insulation sleeves for the high voltage carrying wires.
Two more rails attached to the other ends of the choke and transformer. Another rail connecting these two for mechanical stability:
More bolts added which are needed to screw on the bottom lid, once the amp is inserted in the wooden frame.
Now everything is ready to be tested. After the test is complete the amp is put into the frame:
The bolts line up with holes in the bottom lid:
Through these everything is securely held in place by screws:
The bottom lid also carries the rubber feet on which the amp rests:
The finished amps:
Step by step testing and measurements will be covered in part 5. Stay tuned!