Early Vox Amplifier Circuit Diagrams
Detail of JMI circuit diagram OS/001.
Below a list of the circuit diagrams currently known for early Vox amps - late 1957 to early 1962. Some have been published (reprinted), others not. The first column gives the number of the sheet if one exists: "s.n." = without number (sine numero). The second column indicates the title/thing. The third column has the initials of the compiler - DWU = Derek Underdown; JB = John Bell. The last column gives dates and other details.
In some instances several sheets with the same number survive but with different levels of addition - OS/010 being a case in point. In all but three sheets Jennings is "Jennings Musical Industries Ltd", the exceptions being OS/005 (AC15 Amplifier no. 2), OS/008 (AC/10 Amplifier no. 3), and Vibravox no. 2 - "Jennings Organ Company Ltd".
Arrangement is chronological for the most part. The list will be expanded with new info and further details shortly.
s.n.
Vibravox
no date.
s.n.
Vibravox
DWU
03/03/58.
OS/001
Vibravox
no date. Panel illustrated at the head of this page.
OS/001A
Vibravox
no date. Contents of the cans potted with araldite.
s.n.
Vibravox 2
DWU
08/04/60. For the AC15 Amplifier no. 2. Jennings Organ Co.
OS/002
AC1/15
DWU
04/03/58. Addition dated 10/11/58.
s.n.
AC15 no. 1
DWU
04/03/58.
OS/003
AC2/30
no date. AC30 Amplifier No. 1.
s.n.
G1/10
DWU
06/03/58. Circuit with 6BW6 power valves.
OS/004
G1/10
no date. Circuit with EL84 power valves.
OS/005 (a)
AC/15 no. 2
04/12/59 Jennings Musical Industries Ltd.
OS/005 (b)
AC/15 no. 2
04/12/59 Jennings Organ Company.
s.n.
AC1/15
DWU
04/12/59. Vibravox included. AC15 Amplifier no. 2.
OS/006
AC6
DWU
08/12/59.
OS/007
AC/30
DWU
01/01/60 AC30 Amplifier no. 2.
OA/030
AC/30 no. 2
DWU
01/03/60 Redrawn 26/07/63.
OA/031
AC15 no. 3
DWU
29/04/60. Addition dated 07/02/61.
s.n.
AC15 no. 3
DWU
29/04/60. Same date as above.
s.n.
AC15 no. 3
JB
07/02/61. A large version sheet of OA/031.
OA/032
AC30/4
DWU
29/04/60. Addition dated 07/02/61.
A/026 (a)
AC30/6
DWU
29/04/60. Additions to 11/09/64.
A/026 (b)
AC30/6
DWU
29/04/60. Additions only to 1963 (?).
OS/008 (a)
AC/10 no. 3
DWU
no date. AC10 Amplifier no. 3. Jennings Musical Industries Ltd.
OS/008 (b)
AC/10 no. 3
DWU
09/09/60. Changes to 14/09/64. Jennings Organ Co.
s.n.
AC/10 no. 3
DWU
09/09/60.
OS/009 (a)
AC/2
JB
09/12/61.
OS/009 (b)
AC/2
JB
09/12/61. Mods added 03/04/62 by JB.
s.n.
AC/2
JB
09/12/61. Mods added 03/04/62 by JB.
OS/010 (a)
Top Boost
JB
11/12/61. Addition of 11/12/61 by JB.
OS/010 (b)
Top Boost
JB
11/12/61. Addition of 14/06/63 by JB. Mentions A/026 (AC30/6).
OS/010 (c)
Top Boost
JB
11/12/61. Issue for 15/02/65 added. Mentions A/026 (AC30/6).
A62-005
Reverb
JB
30/01/62. In conjunction with OS/010.
OS/011 (a)
Reverb
JB
30/01/62. No additions.
OS/011 (b)
Reverb
JB
30/01/62. Redrawn 06/11/64. Cliff Richard Reverb.
