Kawasaki, Kanagawa, Tokyo | 2021 – Kagura 211 parallel single ended monaural power amplifier has been accomplished by putting every know-how that Audio Note/Kondo created.
The world of elastic and coordinated sounds can be delineated only by analog amplifier, where music breathes of original sounds are brought back.
The new perspective flagship power amplifier is how Audio Note/Kondo would really like to be listened to by those who have been indulged in the deep charm of music.
Circuit design is configured with 12AU7～6SN7 x2 for amplification and 6SN7 x2 (cathode follower) for the driver stage to powerfully drive the large-scaled transmitter 211 tube.
These circuits are independently powered by grand-scale, low ripple and low impedance power supply sections supporting high purity amplification stages. Further, in order to attain prime audio quality expected from Kagura, each part stage has been re-examined and newly developed.
Grand-Scale Power Supply Circuit
There are total of 3 power supply transformers that are employed; B power supply transformers above the rear section of the chassis, and amplifying heater transformers and rectifier heater transformers inside the chassis. Further, 4 choke coils are installed to form 3 system power supply circuits with 4 different voltages +/-200V, +450V, and +950V.
Powerful and high grade power supply section with oil capacitors rated at 1000V withstand voltage, and newly developed cut-core type choke coils. In addition, two power cables come with one unit of Kagura due to the fact that main power supply and heater power supply are separated from AC inlet.
By modularizing voltage amplifying section, the merits of manual wiring and shortening of paths have been realized. By placing 3 system decoupling capacitors quite near each module, high purity signal loops could be formed in each stage.
Compactly arranged 211 output tubes and the near heater peripheral section are placed at very near the amplification unit so that from the first stage tube to output tube base could be stowed in a compact space eventually minimizing the wiring travel to the utmost limit. The 211 heather circuit is mounted with large capacitors (40000uF x2) to minimize ripple elements while residual noise level could be attained quite low thanks to employing hum balancer circuit.
High Grade Parts
Between amplification stages we employed newly developed electrode oscillation proof silver foil capacitors contributing to the improvement of sound density.
Instead of conventionally used EI core choke coil, we have developed cut-core type anew for drastic improvement in sound quality natural and strain-free by having removed unpleasant signals.
Kagura’s pure silver coiled output transformer handles output impedances of 4, 8 and 16Ω. The setting is preset for 4Ω and 8Ω for speaker impedance in the factory.
|Product||211 parallel single ended monaural poweramplifier|
|Rated power||50W @1kHz, 5% THD|
|Frequency response||8Hz ～ 55kHz (+0dB, -3dB @1W)|
|Input / Impedance||RCA x1(unbalanced) / 70kΩ,
XLR x1(unbalanced, 2:HOT) / 70kΩ
|Output||4Ω, 8Ω, 16Ω (2 outputs factory preset)|
|Noise||Less than 0.5mV|
|Vacuum tube||211 x2, 6SN7 x2, 12AU7 x1, GZ34 x4|
|Dimension||320mm(W) 370mm(H) 558mm(D)