Table Of ContentDecuphase
C-260
ENTO EENE ol Bs, ER
The unparalleled performance of the new Accuphase C-260
Stereo Control Center sets a new standard for the times.
Dependability is built in with features such as Class-A push-pull
circuits with exclusive power supplies that control line
amplifiers for a balanced transmission system. And the
complete twin mono construction incorporates independent
power transformers. The versatility of the innovative C-260
makes it a unique and powerful stereo control center.
A preamplifier or a "Control Center", as we call it source of sound deterioration, The resistor element operated in the balanced signal transmission con-
here, ls positioned between the power amplifier and of the control is polished very precisely to reach a nection as shown in Fig. (a). Even when unbal-
such musical sources as a CD player, analog turnt- mirror-like smoothness. This newly employed vol- anced external equipment is connected to the in-
able, tuner, DAT recorder, etc., conveniently con- ume control rotates the resistor elements unlike the puts, outputs or both, the new balanced line am-
trolling the signal traffic and adjusting the signal conventional volume control, in whioh the collectors plifier circuit of the C-260 simply grounds the nega-
volume to any desired level. This is the main func- rotate. Thus, it successfully reduces the number of tive signals, while maintaining its original circuit
tion required of a preamplifier. However, it must metal joints, which have been a source ol sound configuration functioning fully as an ideal balanced
transmission system. In other words, the circuit,
also provide absolutely uncolored sound reproduc- deterioration, resulting in a remarkable improve-
tion whereby the listener will not even notice its ment of the distortion characteristics. through which signals pass, remains the same
existence. The C-260 provides a numobf feuncrtio ns worthy whether or not it is used with balanced or unbal-
Employed by the very first model of the C-200 to its designation as a "Control Center”. All func- anced connections, thus successfully eliminating
series preamplifiers is ap ure complementary push- tions, other than those most commonly used, are any changes in the signal path that may deteriorate
pull amplifier circuit, a truly ideal amplification cir- logically organized under the hinged front sub- sound quality.
panel. This assures the utmost ease of operation This ideally balanced circuit based on the signal
cuit topology. As the series advanced, such addi-
tional circuit features as a direct coupled and cas- while maintaining a simple overall appearance. transmission theory, guarantees remarkably im-
code bootstrap circuit were added. Further, a bal- We are confident that the C-260 Incorporates all proved S/N characteristics, thanks to the excellent
anced signal transmission circuit was very quickly the technical know-how that Accuphase has noise reduction when employed in a balanced con-
employed for both the input and output stages, in accumulated since its foundation. It combines nection
order to further improve the audio quality. superb performance characteristics, excellent op-
In the C-260, the circuit perfection has been erational functions and beautiful design, allo fwh ich Excellent Basic Characteristics for Line Input
furthered by successfully developing an output cir- have been refined to their utmost, bringing you a ‚Amplifier
step higher in the fascination of sound reproduc- Fig, 3 shows a circuit diagram for the balanced
cult consisting of a single amplifier and no trans-
former. This is an ideally balanced signal transmis- tion input amplifier. It is based on Accuphase's original
sion circuit, which does not require a common differential complementary. push-pull input am-
ground. plifier and cascode push-pull amplifier circuits. The
Accuphase's original logic relay control circuit High Quality, Ideally Balanced Transmission input stage, in which a high-gm type FET is employ-
has been emplotyoec ondtro l compauldieo sxign al Line Amplifier ed, consists of a constant current load type cas-
Fig, 1 is a circuit block diagram of the C-260. The
ntroatf fice. xpTohsei nrge laythse useeldec tarrice icn oan tsaecatlse d toc asaiirn,g ,w htihcuhs simplified functional explanation of the balanced icnopduet acimrpcluíift.i er,T hew hCe-n2 60t heo pienrpautte ss igansa las baarlea nccoend-
guarantees many years of perfect operation and line amplifier stage is shown in Fig. 2. As shown, nected to the positive (+) and negative (—) termi-
AMP2 and AMPS complement each other's opera- nals. It operates as an unbalanced amplifier, when
high quality sound reproduction. tion. Asa result, no common ground (G) exists in the the input signals are connected to the common
Special attention has been paid to the audio
circuit, thus forming an ideal amplifier circuit, when
volume control, which normally tends to be a big ground and positive terminals. Naturally, these am-
A Newly De
trol
Presence Control Offers a Versatile 4-Point, 6-
Frequency Control
Fig. 5 Circuit configuration of the
Presence Control
ono Equalizer Amplifier
AC Cartridges
Presence control
characteristics
INTERIOR LAYOUT
channel po transformer
hannel pow
nel fiterc apacitor:
innel fi
Each amplifier unit and filter capacitors mounted on
the mother PC board and peripheral circuit boards
Other Features
ar
quency energy at
terist
wide range of MM
cartridges. The
cuit for MM
phono cartridge
or 36dB for MM Balanced to Unbalanced Transmission Conver-
sion Amplifier Exclusively for Tape Output.
Highly Reliable Logic-Relays Permit Straight For the tape recording output Loudness
and Short Signal Paths. e signal iransi compensator
s of thep reamplifier ist or rt b r characteristics
n the sam
that they tend tod egrade
handled. put terminals, to
joke, the C-2€ possibilities with ver rogram source
Frequency!
vith nitroge Unsurpassed Input/Output Versatility For Multi- ‘Sub-sonic filter
the relay are a gold p ple Program Sources characteristics
speci ly oped
unication equipment use wa toa
input put com
prerequisites of a "€ Luxurious Persimmon Wood Sidepanels
Provided are three pa The
airs of unbalance 3 t panel
(AD) airs e: N
The phono equalizer amplifier has a
dedicated power supply unit and
features an exclusive input circuit
compatible with all cartridges,
including MM and MC.
The logic relay control circuit board
incorporates highly rellable sealed
relays charged with nitrogen.
FRONT/REAR PANELS
Remarks
"These switched and unswitched AC
outlets may not be supplied depending
on the safety standards or regulations
applicable in the particular country to
where the unit is destined.
From the 1owling winds of time and
change emerges the Accuphase traditior
hones polished and shining.
Meet the new tradition
enrich life through technology
GUARANTEED SPECIFICATIONS +L oudness compensator (when the audio volume set to
(Guaranteed specifications are measured accordi —— BUANLBAANLCAEN CED C ~3048)
ndard AS-490, AD denotes Analog Disc input
Performance Guaranty
All Accuphase product sp stated + Attenuator
+ Frequency characteristics UNBALA! = REC OUTPUT
BALANCED INPUT: [CD/LINI MMI/MM2] — BALANCED OUTPUT: + Semiconductors
1.0 to6 00,000H a M — UNBALANCED OUTPUT
oH +0, = = REC OUTPUT
CED INPUT: [CO/T AILINEITAPE PLAY D OUTPUT.
ED OUTPUT
AD [MC] INPUT Z REC OUTPUT.
e Presence controller
+ Total harmonic distortion
0.005% ( termina
+ Input sensitivity and impedance
Input termin
Rated output
AD MMT
MMz a
AO NC 7000,
BALANCED ET]
UNBALANCED EA
+ Rated output and output impedance
BALANCED OUTPUT:
UNBALANCED OUTPUT:
TAPE RE!
+ Headphone jack
Sultable impedance 4 to 6000
+ SIN and input converted noise
Input shor-cireulted
Output voltage vs. THD ‘Output voltage vs. THD-
(Balanced CD input to balanced output) (Unbalanced CD input to'unbalanced output)
AD MN
AD MM2
ADC
ALANCED
BALA
BALANCED OUTPUT
UNBALANCED OUTPUT
TAPE REC 7.0V. RCA jack for AC input
+ AD maximum input voltage (distortion ratio 0.005%, 1kHz)
MM INPUT: 250mV
MM2 INPUT: 125mV a E J
MC INPUT: Bm
+ MiAnLiAmNuCmE Dl oOaUdTiP UmTp.e dance 6000 Input voltage vs, THD (MM input to tape output) Input voltage vs, THD (MC input to tape output)
ED OUTPUT: 1k)
ccupnase
ACCUPHASE LABORATORY INC.
K915Y 851-0103-00(G3) PRINTED IN JAPAN
