Altec 1591A Mod
Altec 1591A mod Chassis Inside view
This pic shows the gain switch added to the rear of the VU meter. Front panel is easy to open so switch is readily accessible. On the left a small plastic bag can be seen that holds some of the pre-mod parts, just in case one wants to go back to stock.
Altec 1591A mod close up on gain switch
This pic shows a close up of the gain switch. “NORM” position is meant for typical use after mod is installed, for use with line level signals. “+22 BOOST” is meant for use when input signal is unusually low or to get back to the mega compression of an umodded 1591A.