Howard_johnstone

The first thing to do is to replace/upgrade the small rectifier diodes to a std. bridge. Any small bridge will do such as GBJL or KBJ1510. The single main capacitor (AC-coupled) can be replaced with 15 or 18mF/63V that have the same size as original at low cost. Do not use the same values as the original 2200uF/63V, this is especially so with the 1000uF/35V output capacitors that should be replaced with 8700uF/35V at the same size as original. (AC-coupled amps where regarded as inferior as they could not muster the 20mF output capacitors that is required for full bandwith, 20-20kHz.) This is no longer the case. All this is important to observe especially so if you are going to run the receiver at high volume (full output).