Accuphase C 200 L Brochure

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Accuphase C 200 L Brochure

Extracted text from Accuphase C 200 L Brochure (Ocr-read)


Page 4

phenomena may result To realize a straight
and shortest signal path, relays are placed at
locations on the signal path of the C-200L
where a switch is required. These relays are
electronically controlled by a logic circuit to
swnch over inputs. The employed relays are of
airtight type that is exclusively used for audio
equipment and designed to prowde high re-
liability and durability

IMPEDANCE AND GAIN
SELECTORS ENSURE BEST
INPUT MATCHING

The C»2OOL is provided with excellent input
matching to various MC cartridges which come
in such wide variations of impedances and
output levels, For example, output impedances
of MC cartridges vary all the way from 2 ohms
to almost 50 ohms, a difference of 20 or 30
times, Likewise, their output voltage levels vary
from 001 mV to 0 5 mV, 3 difference of 50 times
(34 dB), Although matching MC cartridges to
the head amplifier is not as critical as for
transformer coupling, low output impedance
cartridges should be coupled to low input
impedance to obtain best performance,

To accommodate this wide variety of MC
cartridges and preserve fine control of sound
quality. the C~2OOL provides a chOice of input
impedance of lo ohms, 30 ohms or 100 ohms

This permits coupling MC cartridges of
about S-ohm impedance to a load of 10 ohms
or 30 ohms. and cartridges of over 10-ohm
impedance to either a load of 30 ohms or 100
ohms for closer matching.

Also to accommodate MC cartridges with
very low output levels, a Gain Selector switch in
the C~200L raises the gain to 32 dB instead of
the normally operated head amp gain of 26 dB,

Signal input levels to the head amplifier are
based on RIAA recording characteristics that
drop in the low frequencies and rise in the high
frequency range, A signal at 20,000 Hz would
be about 20 dB, 10 times that of a signal at
1.000 H2, Therefore, the maximum input level of
head amplifiers must extend at least to a level
of 50 mV. ExtenSion is provided up to 150 mV in
the C-200L and this wide dynamic range gives
it ample margin to handle any input pulse signal
voltages,

GOO-OHM BALANCED TYPE
OUTPUT CONNECTOR FOR
LOW NOISE LONG CABLE
CONNECTIONS

The use of a 600-ohm balanced type cable
network has long been a standard practice by
broadcasting stations, and also for commercial
audio applications when long signal carrying
cables are required, since it effectively pre-
vents noise pickup. The C-ZOOL is equipped
with an output connector for connecting such
balanced cables. The principle is shown in Fig,
4 in which equal positive and negative signal
voltages in relation to ground potential are
transmitted by the balanced cable network.
Even if unwanted disturbances are picked up
by the cable, the positive and negative noises
appear in the same phase and are effectively
canceled out by a phase inverted circuit in the

input stage of the power amplifier In short,
such a balanced tine prevents norse pickup
and ensures minimum-deterioration or signal
sound quality from long cable connections
However. the components on both Sides must
be equipped with 600~ohm balanced type
cable connectors.

WIDE TONE CONTROL
CHOICES

Separate tone control circuits are provrded for
the left and right channels Tone is varied with a
10-step rotary switch in 1.5 dB steps The
circuitry also offers switch selection of turnover
frequencies, which further widens tonal varia-
tion choices in the lower and high frequency
ranges with 200 Hz and 500 Hz bass turnover
frequency points, and 2 kHz and 7 kHz treble
turnover frequencies. Also available is an ON’
OFF Switch with which the tone control circurtry
can be cut off or activated as desired.


TWO-STEP LOUDNESS
COMPENSATOR

A twostep Loudness Compensator Switch
provides a choice of two sound energy balanc-
ing curves to make up for the deficiency of the
human ear to detect certain audio frequencies

Pre amp, Power amp.

Fig. 4 Principle ol the Balanced Type Network

during low level reproduction. A choice of the
two compensating curves are offered, whose
selection is governed by the sound reproduc-
tion level and listening room acoustics. COMP l
provides a +3 dB boost at 100 Hz COMP 2
provides a +8 dB boosl at 100 Hz and a +6 dB
boost at 20 kHz (With volume set at —30 dB)
The degree of the compensation is automatical-
ly adjusted according to the position of the
VOLUME control

COMPLETE TAPE
RECORDER FUNCTIONS

A total of three tape recorders can be con-
nected to this preamplifier (one to the front Sub
Panel) Any two of these machines can be usel
for tape copying from one machine to another,
This can be done while Simultaneously listening
to a completely different program source since
the Copying SWitch is independent


AMPLE NUMBER OF
INPUT/OUTPUT
CONNECTORS
Plenty of INPUT/OUTPUT connectors are availv
able for convenience in handling a large
number of program sources, and conducting
various tests of sound equipment, A total of
eleven inputs include three pairs of DlSC, one
pair for TUNER. four pairs of LINE and three
pairs of TAPE PLAY connectors, This pream»
plifier also has a total of seven outputs that
include four pairs of OUTPUT connectors, three
pairs of TAPE REC connectors and one head-
phone jack, One pair each of DISC, LlNE, TAPE
PLAY, TAPE REC, and OUTPUT connectors
and a Headphone rack are located on the
frontside Sub Panel for convenience in making
tests, etc. and also to eliminate complexity
The DISC input in the Sub Panel is especially
useful for testing turntables and phone car-
tridges