From MetroAmp Wiki
Dagnall, DE Ltd part # C1998 100 watt output transformer. Circa Nov 1967 - 1972. Found in Marshall 100 watt plexi amps.
1.7KΩ primary impedance
1.5" core
most 60's versions had "self leads" meaning the actual copper wire of the secondary windings came right out of the covers and was insulated with colored sheathing. As opposed to typical non-self lead transformers which have PVC coated wires attached to the secondary wires inside the covers.
Color code for Metroamp replica of Dagnall C1998. Color code also applies for the self leads model, the Dagnall C1998V replica.

