Description

Realization of low distortion rate by two-stage configuration
It is impossible to eliminate distortion completely as long as using amplifying elements.
The countermeasure is whether to use a device with good linearity or reduce the number of devices.
C3PR is mounted highly reliable and linearity tube C3g developed by Deutsche Telekom.
C3PR consists only of two C3g tubes and minimizes intermodulation distortion and harmonic distortion in spite of non feed-back.

True balanced transmission is transformer

Complete balanced transmission which is possible due to transformer
The balanced transmission can only be done with a transformer.
Transformer is equipped with the input and output of C3PR, and perfectly balanced transmission is capable.

High performance transformer placed both input and output
Transformers of C3PR that are designed by ourselves and based on many rich experiences for years.
Transformers are the most important electronic components in among key parts that affect the performance of the amplifier, such as distortion, SN ratio, input and output impedance.
Every transformer is developed on the detailed parts design such as core material, wire material, winding thickness, winding ratio used.

Exquisite sound quality
Key technology is non feed-back
A negative feedback circuit was invented in 1927, and the performance of the amplifier improved markedly. However, as you examine it strictly, the negative feedback circuit (servo control) returns the signals that have gone too far to +, unnecessary vibration that restores the signals that have gone too far back to – and causes intermodulation with the audio signal, It becomes a heterogeneous sound compared with the original one. In order not to suppress this vibration, it is necessary to take servo control, or use high linearity components such as amplifying elements and capacitors with non feedback control.

Intermodulation distortion worse than harmonic
What is harmonic distortion means that when a signal passes through the component element, a signal of an integral multiple is output, and in a sense, it can be heard comfortably for humans. Among the distortion, it is intermodulation distortion that is worse, generating uncorrelated signals that are not in the original signal, resulting in an unpleasant sound. For example, when a signal of 1 kHz and a signal of 1.1 kHz pass through a rectifier or an amplification element, a sum signal and a difference signal of the respective signals are generated. 100 Hz and 2.1 kHz were not found in the original signal. The audio signal is a collection of many frequency components, and the frequency component of noise also causes intermodulation and invades the audio signal. This phenomenon occurring at MHz outside the audio band also causes noise to enter the audio band.

Outstanding noise suppression technology
It is source from which noise is generated from contact points of rectifiers and circuits in power supply. Since these noises are sharp rising　noise they occur over the band of 50 Hz to several hundred MHz. Furthermore they cause intermodulation and enter the audio band. After all the sound becomes unnatural. Generally noise is greatly generated by switching power supply as well and the same thing happens. However CS port noise processing technology based on years of switching power supply design greatly suppresses / cuts unnecessary noise and achieves exquisite sound quality.

inner

Each channel on the right power supply and left
One is independent as Hi-Fi unit. power supply The control circuit also works out independently as well.
The AMP circuit does not make up the SN, but the aggregate of the original characteristics creates SN. It is AMP which creates very quietness on hearing.

Switching power supply + analog power supply
It is not too much to say that the sound depends on the power supply that is good or bad C3PR stabilizes all the power supplies appropriate for the reference unit , such as insulation with AC line in multiple stages, and does not cause turbidity of sound. The voltage stabilized by the switching power supply is further rectified by the high-speed response non-feedback analog power supply. From there you can hear a sound like pure flow stream.

Various I / O plug

Various input / output plug
The input can be switchable to unbalanced 4 channels or balanced 2 channels. Each of unbalanced and balanced terminal is equipped with two outputs.

The real value of the preamp depends on attenuator
Resistor switching ladder type, constant impedance attenuator
For variable resistors with contacts sliding on the resistive element, point contact diodes are formed at the contacts, and noise is generated when sound signals pass through, which is the basis of distortion.
In C3PR, resistance ladder is switched by a high reliability relay with crossbar twin structure gold · platinum contact, and attenuation from 0 dB to -60 dB is performed. It can be adjusted in 0.5 dB from 0 dB to -38 dB, and from 1 dB in 5 dB units from -38 dB to -60 dB. By further pushing the knob it is possible to squeeze it down to -70 dB, and you can adjust the volume in 107 stages as a total.

Large viewable display
Large display easily to see
The 25mm attenuator level characters can be clearly confirmed from the remote position. The display brightness can be varied in 5 steps, and it can be adjusted to the brightness of the room.

Balance adjustment
Adjustable the left and right balance to ± 3.5 dB in 0.5 dB step.

Bass boost
Three levels of bass boost can be done in 2 dB steps.

Remote controller
All operations except the POWER switch are available from the remote listening position. Because rechargeable battery is built　in, it is unnecessary to replace for over 5 years. You can charge from the USB terminal of the personal computer.

Product Summary

Stereo preamplifier C3PR

Specification