Grason - Stadler 162K
Grason - Stadler Company
15 Winthorp Street
West Concord, Massachusetts, USA

    The Grason-Stadler 162K is a specially modified McIntosh MC-40 amplifier that was designed to be used as a studio monitor in conjunction with the Grason-Stadler 162 "Speech Audiometer" speech and hearing analyzer.  Electronically the Grason-Stadler amplifier is the same as the McIntosh amplifier with the addition of a VU meter connection, VU meter adjustment control, and an attenuate circuit between the input and first 12AX7 preamplifier tube.  The amplifier pictured above is one of a matched pair of mint GSC amplifiers I have in my collection.  The output 6L6GC tubes that I use on these amps are 1996 Svetlana brand tubes made by the Svetlana Electron Devices Inc. Russia.

Tube Line Up:
6L6GC x 2...Push Pull Audio Output
Solid State Rectifiers

Power Source:
AC...120 Volts

Height...7-7/8 inches
Width...8-1/8 inches

    Learn more about the McIntosh MC40 by visiting Roger Russell's McIntosh History Page web site by clicking on the link below.

Roger Russell's McIntosh History Page

Grason-Stadler's corporate website

    Instruction Manual for the Grason-Stadler Speech Audiometer Model 162.  The schematics and instructions to use the 162K amplifier is included.

    This is a picture of the Grason-Stadler Speech Audiometer Model 162.  It was designed for speech and hearing analyses and has it's own built in amplifier using 6V6 push-pull output tubes.  The 162K amplifier was designed to give an added boost in amplification when required by the user.

Grason-Stadler 162K amplifier schematic.

McIntosh MC40 amplifier schematic.

    This is a comparison of the two input circuits showing the difference between the Grason-Stadler 162K (left) and that of the McIntosh MC40 (right).  The circuit for the Grason-Stadler 162K allows less audio input signal then does the circuit for the McIntosh MC40 but it can easily by rewired to match McIntosh's input circuit.

This web page was last updated: April 7, 2006