Audio Database

The

Accuphase C-17
195,000 yen(September, 1984 release)

Description
 
MC head amplifier developed aiming at transmitting the individuality of a cartridge straight.

C-17 constitutes all the magnification stages from a cascode push-pull amplification circuit, and is.
Cascode connection connected two elements, was operated just like one element, does not almost have the feedback in the core of an element, and there is little generating of noise and it has the feature that linearity is good, covering high frequency from low frequency.
By constituting this in a push pull, it is the amplifier excellent in distortion, noise, and a frequency response.
Furthermore, these circuits were stored in aluminum housing of right-and-left independence, and resonance by a guidance noise and vibration is prevented.

Thorough low noise-ization is performed and low impedance-ization of the NFB loop is attained to adoption of a low noise element, and the noise generated in a difference input circuit.
Moreover, in order to avoid the influence of the noise generated from direct-current servo circuit, S/N of theoretical full limits is realized by returning to the base of a current generator instead of the system which returns to the minus side of differential amplification directly.

The power-source part is using the power transformer for exclusive use for a right-and-left channel, and serves as a mono-construction.
Furthermore, in order to carry the constant-voltage power source only for a right-and-left channel in order to attain low impedance-ization over a broadband, and to make the wiring course of this constant-voltage power supply circuit into the shortest, it has stored in the same aluminum housing as a magnification circuit.

In order to correspond to various MC cartridges and to be able to control sound quality minutely, MC input impedance is considered so that it may change to a three-stage (10ohm, 30ohm, and 100ohm).
When the impedance of a cartridge is around 3ohms, 10ohm or 30ohm is suitable for load. And in more than a 10-ohm class, 30ohm or 100ohm is suitable for load.
Moreover, for the low output MC cartridge, the gain changeover switch is provided in everything but the usual profit of 26dB so that high gain of 32dB can be obtained.

Internal Magnification

Rating of a mode
Form MC head amplifier
Gain 0dB (MM), +26dB, +32dB
Frequency response 20Hz-20kHz+0 -0.2 dB
2Hz-100kHz+0 -3.0 dB
The maximum inlet pressure
(1kHz, 0.005% of distortion)
+ 26dB position : 150mV
+ 32dB position : 75mV
Rated inlet pressure + 26dB position : 0.1mV
+ 32dB position : 0.05mV
Output-power voltage 2.0mV
THD 0.005% (at the time of 20Hz - 20kHz, and the maximum input)
S/N and input conversion noise
Gain Input short-circuit and A compensation EIA S/N
It is S/N at the time of a rated input. Input conversion noise
+ 26dB position : 72dB -152dBV 76dB
+ 32dB position : 66dB -152dBV 76dB
Input impedance 10ohm, 30ohm, 100ohm, a change type
Output load impedance 50ohms
Minimum load impedance 10kohm
The semiconductor used Transistor: 71 pieces
FET: Four pieces
IC: Eight pieces
Diode: 64 pieces
Power supply voltage AC100V/117V/220V/240V, 50Hz/60Hz
Power consumption 30W
Dimensions Width 194x height 142x depth of 371mm
Weight 8.1kg