WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
The stereo 20 circuit changed a little over time, the early version could be prone to overheating. The two main versions can be found here: Leak Circuits
You need to identify which output transformer you have in your unit and then use the approriate schematic.
There's lots of Leak stuff on that site, it's worth a browse. H.J.Leak and Co. Ltd.
The hardcore leakies can be found at hjleak : "H. J. Leak & Co. Ltd."
Morgan Jones describes the Leak 20 as "noisy"....by modern standards. Perhaps one could chase down & correct such shortcomings via subtle modifications. He (Morgan) also notes the 20 also has " a few corners cut", perhaps this could be rectified as well. The Leak enthusiasts quite probably are aware of such shortcomings. Besides replacing most all caps for age issues, I for one would have custom OPTs made...........as I consider these paramount to performance.
any suggestions where one can source a replacement 3watt 100ohm wirewound resistor for this amp? This is the crucial one that drops out if it gets too hot and protects the mains tranny. Lots of different versions available in the uk, any suggestions as to type to go for and supplier?