Early Vox AC30 circuit diagrams
1957 to 1960
To be updated shortly
The circuit diagrams on this page all come from hard copies - sometimes copies of copies - often made numbers of decades ago. It seemed rather redundant to re-post identical copies of things that are already on the web.
The amps encompassed are the AC2/30 of 1957-1958; the AC/30 (AC30 amplifier no. 2) of 159-1960; and the AC30/4, first issued in TV Front cabinets. Circuit diagrams for the AC30/6 can be found on this page.
Click on the images below for larger downloadable versions (around 3200 pixels wide).
Undated, but probably drawn in early 1958. The AC2/30 was brought to market in late 1957 - see this page. The amplifier's circuit derives in part from an amplifier designed by Derek Underdown for JMI organs - two EL34 valves in the power section.
AC/30 (AC30 amplifier no. 2)
The amplifier was brought to market in the late summer of 1959 and remained in production until late Spring 1960 - see this page. Diagram drawn on 1st January 1960. Connections to the sealed Vibravox cans are indicated. Two EL34s in the power section; GZ32 rectifier valve, five ECC83s in the preamp.
Dated 1st March 1960. Traced on 26th July 1963. Effectively the same drawing as above, but titled "AC30 Amplifier".
AC15 no. 3
Included to accompany the circuit for the AC30/4 below - OA/032. Both were drawn up on the same day and modified on the same day.
Dated 29th April 1960 - the date given also on OA/032 below - in the lower information panel. Drawn by Dick Denney (RD). Three changes noted top right, the first dated 7th February 1961.