Audio Database


McIntosh C32 a price point -- unknown (1970 in-the-earlies ?)

The preamplifier born from traditional craft Manship who does not allow compromise.

The output of 12W+12W is obtained to a loudspeaker connecting terminal on the back, and a drive of an X-tend speaker system is also possible by the combined use with an input selector switch.
Moreover, a front headphone jack can be driven also by a dynamic type and capacitor type, and carries the volume for exclusive use.

FET is used for all the input changeover switches.
FET is made to turn on and off on minute DC voltage, and the frequency characteristic is not affected, but the occurrence of the switching matter noise is suppressed.

5 band special-NetWare-program equalizer defeet switchpoint is carried.
A coordination of ±12dB is possible focusing on each frequency of 30Hz, 150Hz, 500Hz, 1500Hz, and 10000Hz.

It is also possible the sound recording of an FM broadcast and to monitor independently, respectively, making the changeover switch only only for a play and for a sound recording become independent, respectively, carrying it, and playing a record.

The logarithm expander circuitry is carried, and noises, such as a hum, hysterics, and a scratch, are decreased at the same time it expands a dynamic range in logarithm and rectifies it.

It is indicating by the function and the operating state of each push-button switchpoint of the front panel is shown by red light emitting diode.

By a power-source interlock outlet circuit (SCR adoption), if the player operates, the power source of a preamplifier will also be automatically set to ON. Moreover, if a player is come by off, a power source will also be in an OFF status.
It is also possible to turn OFF this functionality.

In order that a power transformer may remove a hum and may improve an SN ratio, the Mie shielding is carried out with a copperplate, a silicon-steel board, and metal casing.
It is rectified with 24V Output voltage, and monitor amplifier is supplied.
Moreover, 18V is pressured partially from an Output voltage, and the voltage stabilizer and the OP-amp circuitry are supplied through IC voltage control circuitry.

Four low-noise transistors of a low impedance are used for a Phono equalizer amplifier.
In order to demonstrate this low-noise effect, a 68-ohm feedback circuit is adopted.

All of a loudness circuitry, an equalizer, and a band pass filter consist of ionic bond type electrolysis differential amplifier (OP amp).

The special relay is carried in order to remove the Tran Gent event produced by ON/OFF of a power switch.
This relay operates with a transistor switchpoint and sends the output of a preamplifier to an output-terminal.
The long capacitor of a time constant and a short capacitor are built into a transistor switchpoint,after a power source is set to ON by the former capacitor, a signal is set to ON in about 2 seconds, and a power source is come by off by the latter capacitor -- the relay is controlled so that a signal is come by off in front for a while.

Internal 5

Rating of a mode
Form Stereo preamplifier
Frequency characteristic 20Hz-20kHz+0 -0.5 dB
10Hz-100kHz+0 -0.5dB (at the time of Equalizer OFF)
Distortion 0.05% or less (at the time of 20Hz - 20kHz, and an Output power)
Input sensitivity/impedance Phono1, 2:2mV / 47kohm (65pF)
AUX, Tuner, Tape1, 2 or 3:250mV / 50kohm
A hum and a noise AUX, Tuner, Tape1, 2, 3:IHF 100dB, 90dB (with no auditory sensation weighting)
Phono1, 2:IHF 90dB, 80dB (with no auditory sensation weighting)
An Output voltage/impedance Main output: 2.5V / 5kohm (at the time of a rated input)
Tape output: 0.25V / 5kohm (at the time of a rated input)
A monitor, headphone, and a line output 12W+12W (8 ohms, 20Hz - 20kHz, 0.1% of distortion)
5Vrms (a 600-ohm line, with a level control)
Special-NetWare-program equalizer 30Hz, 150Hz, 500Hz, 1500Hz, 10000Hz
Two octave each frequency bands (a 12dB boost and cut)
line feed character filter A flat and -12 dB/oct. (50Hz or less)
HF filter A flat and -12 dB/oct. (7kHz or more)
Voltage amplification
(decibel, an equalizer, and a filter are flat locations)
Input Main Tape1, 2, 3 Monitor amplifier
AUX, Tuner : 20dB 0dB 20dB
Tape1, 2, 3 : 20dB 0dB 20dB
Phono1: 62dB 42dB 62dB
Phono2: 62dB 42dB 62dB
The semiconductor used Transistor: 67 pieces
IC: 35 pieces
Diode: 62 pieces
FET: Two pieces
Silicon rectifier (SCR): One piece
AC plug socket Automatic ON/OFF plug socket (green): Two lines
Switchpoint type plug socket (black): Four lines
Power source AC120V, 50Hz/60Hz
Power consumption 25W-85W
Dimensions Main unit: Width 381x height 127x depth of 330.2mm (pan nowait-lock included)
Front panel: Width 406.4x138.1mm in height
Weight 11.79kg (at the time of an original packaging: 16.33kg)