McIntosh C32

Commentary

This is a preamplifier created from uncompromising traditional craftsmanship.

An output of 12W + 12W is available at the speaker connection terminal on the rear panel. When used in conjunction with an input selector switch, it is also possible to drive an active speaker system.
The headphone port on the front can be driven by either a dynamic type or a condenser type and has a dedicated volume.

FET is used for all input changeover switches.
Minute DC voltage turns ON/OFF the FET, does not affect the frequency characteristics, and suppresses the generation of switching noise.

Equipped with a 5-band program, equalizer and defeat switch.
Adjustment of ± 12 dB is possible around 30 Hz, 150 Hz, 500 Hz, 1500 Hz and 10000 Hz.

It is equipped with separate switches for both playback and recording. It is possible to record FM broadcasting while playing a record or monitor each of them independently.

Equipped with a logalism expander circuit, the dynamic range is logarithmically expanded and corrected, while noise such as hum, hiss and scratches is reduced.

The red LED indicates the function and shows the operation status of each push button switch on the front panel.

The power sensitive outlet circuit (SCR) automatically turns on the power of the preamplifier when the player operates, and turns off when the player is turned off.
This function can also be turned OFF.

The power transformer is triple shielded with copper plate, silicon steel plate and metal case to remove hum and improve the SN ratio.
It is rectified at 24 v output voltage and supplied to the monitor amplifier.
In addition, 18 v is divided from the output voltage and supplied to the constant voltage circuit and OP amplifier circuit through the IC voltage control circuit.

The Phono equalizer amplifier uses four low-noise transistors with low impedance.
To achieve this low-noise effect, a 68-ohm feedback circuit is used.

The loudness circuit, equalizer and bandpass filter are all composed of an ion-coupled electrolytic differential amplifier (OP amplifier).

A special relay is mounted to eliminate the transient phenomenon caused by ON/OFF of the power switch.
This relay is operated by a transistor switch and sends the output of the preamplifier to the output terminal.
The transistor switch incorporates a capacitor with a long time constant and a capacitor with a short time constant. The former capacitor controls the relay so that the signal turns ON approximately two seconds after the power is turned ON, and the latter capacitor controls the relay so that the signal turns OFF just before the power is turned OFF.

Model Rating

Type	Stereo preamplifier
Frequency characteristic	20 Hz ~ 20 kHz + 0 -0.5 dB 10 Hz ~ 100 kHz + 0 -0.5 dB (with equalizer OFF)
Distortion factor	0.05% or Less (20 Hz to 20 kHz, Rated Output)
Input Sensitivity / Impedance	Phono1, 2 : 2mV/47k Ω (65 pF) AUX, Tuner, Tape1, 2, 3 : 250mV/50k Ω
Hum and noise	AUX, Tuner, Tape1, 2, 3 : IHF 100 dB, 90 dB (without acoustic compensation) Phono1, 2 : IHF 90 dB, 80 dB (without auditory sense correction)
Output Level / Impedance	Main output : 2.5V/5k Ω (at rated input) Tape output : 0.25V/5k Ω (at rated input)
Monitors, headphones and line outputs	12W + 12W (8 ω, 20 Hz to 20 kHz, 0.1% distortion) 5 Vrms (600 Ω line, with level control)
Program equalizer	30 Hz, 150 Hz, 500 Hz, 1500 Hz, 10000 Hz 2 octave frequency bands each (12 dB boost and cut)
LF Filter	Flat and -12dB/oct. (50 Hz or less)
HF filter	Flat and -12dB/oct. (7 kHz or more)
Voltage amplification (dB, equalizer and filter in flat position)	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
Semiconductor used	Transistor : 67 IC : 35 Diode : 62 pcs FET : 2 Silicon Rectifier (SCR) : 1
AC outlet	Automatic ON/OFF outlet (green) : 2 systems Switch-type outlet (black) : 4 systems
Pwer	120 VAC, 50Hz/60Hz
Power consumption	25W ~ 85W
External dimensions	Body : Width 381x Height 127x Depth 330.2 mm (Including Panlock) Front Panel : 406.4 mm W x 138.1 mm H
Weight	11.79 kg (Packed : 16.33 kg)