The AC50 was developed specifically for the Beatles so fans could hear them better live. The two EL34s produce around 50 watts. Both channels feature the "Top Boost" circuit. This is the Mark III version introduced in 1965 when Vox changed from a tube rectifier to a solid state rectifier. The power tubes are EL34 (2), 12AU7 (1), and 12AX7 (3).

This 1965 AC50 was recently serviced and has original transformers, Tolex, grill cloth, knobs, handle, pots, and just a few replaced caps and resistors. The input jacks have been replaced due to the original ones being defective. It has been updated to more modern standards with the addition of a 1/4 inch speaker jack and a grounded 3 prong plug with an XLR connector. All preamp tubes are vintage Mullard and Brimar. The unlabeled EL34s appear to be vintage as well.

With any vintage tube amp, it is highly advisable to get it serviced for safety and reliability as the electrical component values have likely drifted outside of specification over time. Therefore, the amp may not perform as it should and the chance of damage to critical components is increased.