25-10-2023, 03:43 PM
Hi Gents, lots of valid points raised.
Blackening of the primary can certainly be due to leaky caps etc, but can also be caused by "green spot" corrosion and leakage between turns due to paper insulation and single insulated wire being used.
Much better to use modern Grade 2 (double insulated) wire and omit the interlayer insulation.
Note that on high spec transformers, used on amps with feedback applied, problems can be caused if the winding sequence is altered due to varaitions in interwinding capacitance
Ed
Blackening of the primary can certainly be due to leaky caps etc, but can also be caused by "green spot" corrosion and leakage between turns due to paper insulation and single insulated wire being used.
Much better to use modern Grade 2 (double insulated) wire and omit the interlayer insulation.
Note that on high spec transformers, used on amps with feedback applied, problems can be caused if the winding sequence is altered due to varaitions in interwinding capacitance
Ed
