The big question is whether the radio was set up to drive an amplifier. The radio has a single final only and driver. If the old version it is a 1969 final, a 2166 driver, the new version has mosfets in it irf 520 and its driver. The problem is that most people think with that variable power knob and the fact that the manufactures say it runs from 1w on low setting and 4-7w on high doesn't make it so. I have ran across several that have a low setting that was too high to run an amp and over time might cause some problems. It probably is a fairly cheap fix. Good luck.