Arbiter reissues used AC128s. Hendrix also switched to the silicon transistors, but they created additional difficulties on stage, since they are much more susceptible to receiving AM radio signals, which were then audible through the guitar amplifier.
Arbiter reissued their AC128 models, and Jimi Hendrix adopted silicon transistors in his setup. However, these transistors proved problematic onstage as they were prone to picking up AM radio signals, resulting in unwanted audio interference within the amplifier.