-designed and made in U.S.A.-, modern solid-state circuitry, simple screw-in replacement of original transistor circuit... see more-designed and made in U.S.A.-, modern solid-state circuitry, simple screw-in replacement of original transistor circuit board inside amplifier box
simple plug-in conversion allows use of a 1973-85 SI series, internally regulated alternator in place... see moresimple plug-in conversion allows use of a 1973-85 SI series, internally regulated alternator in place of the original externally regulated alternator