Vox AC-50/4 2-Channel 50-Watt Diode-Rectified Guitar Amp Head 1965 - 1966

This 3rd revision of the Vox AC-50 saw perhaps the biggest change -- a diode bridge rectifier replaced the GZ-34 rectifier tube that the amp used in 1964. Though that does make for a little less natural "sag" when pushed, that does make them better as both a pedal platform as well as a workhorse bass amp.