|530,000 yen(May, 2000 release)
Control amplifier which refined all the circuits of C-275, and also raised
completeness based on the technology of C-290V.
The current feedback
type magnification circuit which returns an output signal in the form of current
In this circuit, the impedance of the input terminal by the side of a return
was lowered, current was detected, and the output signal is made by carrying
out I-V conversion of that current with a transformer impedance amplifier.
Thereby, since the impedance of a return input portion is low, many characteristics
are [ that it is hard to generate phase rotation ] sharply improvable by
a little NFB.
The output circuit of a bridge feedback
system is adopted.
Balance transmission is a system which sends
simultaneously the positive/negative symmetrical signal which the phase reversed
mutually, and is excellent in the capability to remove the noise ingredient in
the common mode.
In C-275V, it has a relation of tucking up its sleeves with
a cord which feeds back each output of 2 sets of amplifier to the other party, and the symmetrical signal of +- is sent out by low impedance. Since this
circuit is carried out [ floating of the symmetrical signal of +- ] from the
ground, even if it grounds one side of an output, both of amplifier operates and
an Output voltage does not change.
The line amplifier part has adopted
the pure complimentary push pull circuit, constitutes this from a discrete part
by a current feedback magnification circuit, and makes phase compensation of
each stage light.
The printed circuit board by a Teflon (woven glass
fabric fluoro-resin) base is adopted as a signal transmission circuit.
Teflon has the features, like heat resistance and the high frequency
characteristic with very little (low loss) leak current with a low (high
propagation velocity) dielectric constant are excellent. SN on Hearing
impression is improved by using this Teflon base for an audio circuit.
Right-and-left independence is achieved also with a power transformer
and a filter capacitor, and it has perfect monophonic composition electrically.
Furthermore, the broadband low impedance power source was carried in all the
unit amplifier, and the mutual intervention between amplifier is prevented.
The amplifier circuit of C-275V consists of right-and-left a total of
four unit amplifier, such as line-in and a balance output, and has the
composition of having given each the exclusive power-source part.
in thick aluminum housing and fixed firmly so that these unit amplifier might
not carry out a mutual intervention, and resonance by vibration is prevented.
Since a straight signal course is constituted at the shortest, the logic
relay control system has been adopted.
The encapsulated type relay for
communication industry is adopted as the relay used for this, and contacts are a
plated with gold and a crossbar twin system, and have realized low contact
resistance and quantity durability.
The added type active filter system
is adopted as tone control.
When passing an original flat signal as it is
and changing the characteristic, from this system, the characteristic is made if
needed, and it is made to change according to making it adjust from a flat
signal by it.
The exclusive headphone amplifier circuit which thought
sound quality as important is built in.
The Compensation and Subsonic
Filter which can choose an output phase change button and three kinds of
characteristics are carried.
Volume and the remote commander in whom an
input change is possible are attached.
Although C-275V has composition
only for a line, record playback is possible by extending optional exclusive
phone equalizer unit AD-275V from the rear panel side.
A Teflon (woven glass fabric fluoro-resin) base is adopted as a printed circuit board, and the influence from the outside is suppressed by storing this in a strong aluminum case. The connector of the DIN standard was adopted as connection with a main part, and the fall of the signal to noise ratio is prevented by connecting a magnification circuit with an input terminal by a curtate distance.
the input circuit for exclusive use united with the cartridge of each MM/MC in
this phone equalizer unit, and a two-kind choice is possible also for three
kinds and a profit in MC input impedance.
AD-275V cannot be used for any
models other than C-275V and C-275.
Moreover, AD-275 can be used for C-275V.
(The analog disc characteristic shows the time
of AD-275V extension)
||Stereo control amplifier
AD input: 20Hz-20kHz±0.2dB
|Balanced, Unbalanced :
||3Hz-300kHz+0 -3.0 dB
power / 0.5V output)
|AD MM: 4.0mV/1.0mV/47kohm
0.25mV/0.063 mV/10ohm, 30ohm, a 100-ohm change
AD MC/66dB: 0.125mV/0.0315
mV/10ohm, 30ohm, a 100-ohm change
|An Output power/impedance
||Balanced, Unbalanced output:2V/50 ohm
Tape rec (at the time of AD input): 252mV/200 ohms
|S/N, input conversion noise
|At the time of an Output power
||Input conversion noise
(Distortion 0.005%, 20Hz - 20kHz)
|Balanced, Unbalanced output:6.0V
rec(at the time of AD input): 6.0V
|The AD maximum inlet pressure
|Minimum load impedance
||Balanced, Unbalanced output: 600ohms
Tape rec: 10kohm
||Balanced, Unbalanced input -> Balanced,
Unbalanced output: 18dB
Unbalanced input -> Rec output: 0dB
input -> Balanced, Unbalanced output: 54dB
AD MM input -> Rec output:
AD MC(60/66dB) input -> Balanced, Unbalanced output: 78/84dB
MC(60/66dB) input -> Rec output: 60/66dB
(100Hz), +6dB (20kHz)
||25Hz, -12 dB/oct
|The maximum Dimensions
||Width 475x height 150x depth of 404mm
the time of AD-275V extension: Depth of 413mm
At the time of AD-275V extension:
||Remote commander RC-26
||Phone equalizer unit AD-275V (100,000yen)