Bose 4401 service manual

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SPECIFICATIONS

The 4401 preamplifier offers tour inde
pendent channels from input to output with
a capability of matrix decoding, discrete
fourchannel, or stereo operation. Signals
from all current program sources, both stereo
and quadraphonic, can be processed by due
4401.

The 4401 incorporates unique phono
preamp circuitry. utilizing MET1 (Minimum
Effective Temperature) circuitry accounting
for the ultra-quiet operation of the phono
preamp. .

Optional circuitry for the SO decoder
and the CD4 demodulator is contained on
easily-installed, plug-in modules.*

Internal provisions for an additional tour-
channel module are provided for yet6to-be-
developed four-channel systems.

The tone control circuits. as well as the
high and low filters, can be used to process
a signal prior to recording. Recordings can
bemade on two tape recorders simultaneous-
ly, and tapes can be copied from either tape
recorder.

The 4401 provides separate jacks for the
connection of external equalizers. A rear
channel equalizer by-pass switch allows
equalization of only the front channels with-
out the use of jumper cables for the rear
channels.

GENERAL

Separate left/right balance controls for both
front and rear channels.

Independent front and rear channel tone
controls.

Baxendall tone control circuits for optimum
frequency contour control.

Output amplifiers capable of driving both
low and high impedance heamhones.

Time delay circuitry eliminating turn-on
transients.

Two-position phono capacitance switch for
optimum matching of conventional or CD4
phono cartridges.

Optional SO decoder and CD4 demodulator
plug«ir~ moclules.t

Optional remote balance/volume control.

ELECTRONIC

Input Sensitivity:
Phone 1 . . ......... 2mv@1 kHz
Phono 2 . . 2mv@1 kHz
Tuner . . . . .. 200mv
Aux. . . . 200mv
Tape 1 . . . . 200mv
Tape 2 .................... 200mv

Rated Output:
2v FIMS. ......... Minimum 7v HMS
before overload.

Output Impedance:

600 ohms.
Input Impedance:
Higt Level .............. 100k ohms
Phono (except
CD-4 mode) ............ 47k ohms
Phono (CD-4 mode) ....... 100k ohms

Frequency Response:

High Level-20-20,000Hz ....... 10.2db
FIIAA Phono-Equalization ..... i1db
Distortion:

Harmonic Distortion <0.2%, 20-20300
Hz at rated output. -
IM Distortion S 0.2% at rated output.
Hum and Noise:
Him Level . . . . Minimum 80db below
rated output. Noise
typically 90db down.
Phono ......... 500 pV A weighted.
(Unweighted, typically
less than 1 'mV.)

Low Filter:
-3db@70Hz, Gdb per octave attenuation.
Hiyt Filter:
~3db@7kHz, 12db per octave attenuation.
Tone Control Ramp:

Bass ................ 115db@50Hz
Treble. . . . 1'15db@20kHz
Volume Muting. . . ........... -20db

POWER REQUIREMENTS

Voltage ...... 105-130 Vac or 210-260 Vac
Frequency ........... 50-60 Hz (ac only)
Maximum power consumption. . . . 30 watts

MECHANICAL

Dimensions:

6" hid! x 18" wide x 13 1/8" deep.
Weidlt:

12 pounds.

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