
Accuphase C-260 |
|
370,000 yen(April, 1991 release) |
Control amplifier developed as a succeeding machine of C-200 series.
The
balance transmission system is adopted as a line amplifier part.
Line-in
amplifier is constituted from an input differential complimentary push pull +
dregs cord push pull circuit, the input stage FET circuit has also become a
dregs cord + constant current load, and high gm element is adopted as FET.
And if it inputs into both + (being un-reversed) and - (reversal), and a
reversal input will be carried out to balanced input amplifier and it will input
into being a ground and being un-reversed, it will become un-reversed type
disequilibrium amplifier.
Furthermore, it has direct connection amplifier
composition to which direct-current servo was applied.
Newly developed 4
linkage volume control machine is adopted as volume.
The resistance object
of specular surface finishing especially with a small distortion is adopted, and
by specular surface-ization, the distorted characteristic is good, and it excels
in antiwear quality, and also what spoils sound qualities, such as grease,
between a brush and a resistance object is not applied.
Moreover, unlike the
structure of general volume, the resistance object rotated, the portion of the
brush was fixed, and it came out to the directly exterior as a terminal, and by
this, the metal joining section decreased to three places from five places, and
the improvement in sound quality is achieved.
- (reversal) of an input balance circuit, and + (being un-reversed) --
this Attenuator goes into both, and since it is right-and-left channel
linkage, it is considered as four structures which stood in a row.
The power-source part is considering each of equalizer amplifier, line amplifier, and presence control amplifier as the independent composition.
Furthermore, the exclusive power transformer was formed in each right-and-left
channel, and it has separated into it completely electrically.
Moreover, it
is the unit amplifier with which each amplifier made the right-and-left channel
become independent also mechanically, and right and left and interference
between each unit are prevented.
The newly developed amplifier only for
direct connection system headphone is carried.
The presence control
which controls six kinds of frequency 4 point is carried.
It considers so
that four most effective points can be adjusted on music expression, and the
variable store of frequency has become six kinds 4 point.
The inside compass
is 500Hz and 2kHz in center frequency, and 500Hz controls 2kHz of vocals etc. to
expression of a rhythm musical instrument again. Moreover, Q which determines
the sharpness of a crest has chosen Q= 0.707 from which a natural change is
obtained based on the audition result of extensive program sauce.
Low-pitched sound and the loud sound can choose two kinds of frequency,
respectively, and can adjust whole energy balance and atmosphere.
The
composition of presence control consists of combination of few added type
filters of sound quality degradation, and has prevented the characteristic and
sound quality degradation by selecting carefully and using the element focused
on sound quality. Furthermore, it is considered so that it may separate from a
signal course in the state of the presence control off.
The equalizer
amplifier part has composition equipped with the exclusive input circuit which
matched the cartridge of MM and each MC.
At the time of MM input, it is made
to consistent with the high-output impedance of a cartridge, constitutes from an
FET element of high S/N, and is at the MC input time,Since a minute signal is
received by low impedance, little reproduction of noise is enabled by
constituting the difference input circuit by a low noise element, and attaining
low impedance-ization of a NFB loop.
In accordance with the output of a
cartridge, 60dB can be chosen in MC and the profit can choose 30dB and 36dB by
MM.
The logic relay control circuit which uses the relay for
communication industry which used nitrogen gas enclosure and a plated-with-gold
contact for the audio change portion is adopted, and signal degradation by
leading about of excessive wiring is prevented.
Balance imbalanced
conversion amplifier for exclusive use is carried in the recording output for a
balance input. Thereby, the balance input can treat tape relations like other
imbalanced inputs.
Hearing impression at the time of small volume
reproduction is rectified, and the loudness Compensation switch which prepares
energy balance is carried.
It is +4dB in 100Hz : +6dB-20dB o'clock at the
time of volume control position-30dB, and the degree of compensation is
automatically adjusted by the volume control position.
The Attenuator
switch with possible making it decrease to -20dB by one-touch is carried.
The Subsonic Filter is carried.
The upper surface bonnet gave
the gold tone scratch hair line to thick aluminum hair line finishing, the front
panel was given to aluminum, and both sides have attached the board of natural
persimmon finishing.
|
Form |
Stereo preamplifier |
Frequency response |
balanced input (CD, Line) : |
1.0Hz-600kHz+0 -3.0 dB
20Hz-20kHz+0 -0.2
dB |
CD, Tuner, Line, Tape Play : |
1.0Hz-600kHz+0 -3.0 dB
20Hz-20kHz+0 -0.2
dB |
AD input: 20Hz-20kHz±0.2dB
|
THD |
0.005% (with all the input terminals)
|
Input sensitivity/impedance
(at the time
of an Output power / 0.5V output) |
AD MM1:8.0mV/2.0mV/47kohm
AD
MM2:4.0mV/1.0mV/47kohm
AD MC: 0.25mV/0.063 mV/100 ohms
Balanced:
252mV/63mV/40kohm
Unbalanced: 252mV/63mV/20kohm |
An Output power/impedance |
Balanced output: 2.0V/50 ohm
Unbalanced
output: 2.0V/1 ohm
Tape rec: 252mV/200 ohms |
Headphone jack |
Conformity impedance: 4ohms - 600ohms
|
S/N and input conversion noise |
Input terminal
|
Input
short-circuit IHF-A compensation |
EIA S/N
|
Rated input S/N |
Input conversion noise
|
AD MM1: |
96dB |
-138dBV |
85dB |
AD MM2: |
92dB |
-140dBV |
86dB |
AD MC: |
80dB |
-152dBV |
83dB |
Balanced: |
112dB |
-124dBV |
94dB |
Unbalanced: |
116dB |
-128dBV |
96dB
|
|
Maximum-except-take-off level
(0.005% of
a distortion, 20Hz - 20kHz) |
Balanced output:7.0V
Unbalanced
output:7.0V
Tape rec:7.0V |
The AD maximum inlet pressure
(1kHz,
0.005% of distortion) |
MM1:250mV
MM2:125mV
MC:8mV
|
Minimum load impedance |
Balanced output: 600ohms
Unbalanced
output: 1kohm
Tape rec: 10kohm |
Gain |
Balanced input->Balanced output: 18dB
Balanced input->Unbalanced output: 18dB
Balanced input->rec
output: 0dB
Unbalanced input->Balanced output: 18dB
Unbalanced
input->Unbalanced output: 18dB
Unbalanced input->rec output: 0dB
AD MM (1/2) input->Balanced output: 48 / 54dB
AD MM (1/2)
input->Unbalanced output: 48 / 54dB
AD MM (1/2) input->rec output: 30
/ 36dB
AD MC input->Balanced output: 78dB
AD MC input->Unbalanced
output: 78dB
AD MC input->rec output: 60dB |
Presence control |
Four band systems
Frequency: 8kHz [ a
40Hz/100Hz change, 500Hz, 2kHz, and ]/20kHz change
Variable range: ±10dB
|
Loudness Compensation |
+ 6dB (100Hz, Volume-30dB) |
Subsonic Filter |
17Hz, -12 dB/oct |
Attenuator |
-20dB |
The semiconductor used |
Transistor: 59 pieces
FET: 25 pieces
IC: 26 pieces
Diode: 57 pieces |
Power supply voltage |
AC100V/117V/220V/240V, 50Hz/60Hz
|
Power consumption |
19W |
Dimensions |
the width 475x height 149(piece -- it
includeds) x depth of 375mm |
Weight |
18.4kg |
|
|
|