As a power amplifier component in the SU-V900, the tone-quality design know-how of a digital direct drive is used. The power amplifier portion, which formerly consisted of a single unit, now consists of two units: a class AA power amplifier with voltage amplification of 1 (0dB) and a flat amplifier with voltage amplification of 30dB.
The 0dB power amplifier has excellent transmission qualities, including a low noise level, allowing it to avoid voltage amplification. The 0dB amplifier’s operational stability is achieved by combining the original classAA circuitry, which shares voltage management and an electric-current control with a separate amplifier, and a floating power source.
By placing a 30dB flat amplifier in the shielding case of a preamplifier part, it has prevented the excessive current of a power amplifier part output stage from having an adverse influence on a power amplifier part input stage.
These stream compositions have excelled by achieving super-low distortion and speaker driving capacity at the same time.
The right-and-left independence of the mass transformer of 170VA is carried in the power-source component. This transformer is encased with a resin shielding case and employs an oxygen-free-high-conductivity-copper line to reduce equipment oscillation and magnetic radiation. Lower the amplifier’s input stage by attaching it.
The electrolytic capacitor contains the newly developed X-Pro dual capacitor. This capacitor disables two electrolytic capacitors for power sources, one on each side, in a resin box with a copper cap, and the equipment oscillation and electromagnetic radiation are decreased by packing vibrational absorption material.
The power amplifier section used a twin monophonic stream composition, which divided and organized the right and left channels. Having a T-type stream composition that severely insulated the preamplifier part reduces cross-interference between the right-and-left channels by electromagnetic waves from a big current of a power amplifier component.
Furthermore, a hard-to-vibrate chassis construction is used, such as putting the power amplifier on either side of the board bending the chassis of 2mm thickness independently, and also fixing the darkroom and a rear surface board by two center angles.
Electrical machinery and magnetic noise are dealt with by attaching a severe shielding board to the input unit.
Each component is made up of parts such as a high purity OCC wire rod and a PXS electrolytic capacitor.
Using the direct functionality of the power amplifier, a simple connecting of a signal line — high-purity signal transmission is realized.
|<Power amplifier part>|
|Effective output||100W+100W (20Hz – 20kHz, T.H.D 0.007%, 6ohms)|
|THD||0.003% (20Hz – 20kHz-3dB, 8ohms)|
|Dumping factor||110 (8ohms)|
|Frequency characteristic||Phono:RIAA standard curve}0.2dB|
tuner, compact disk, Tape1, 2, DAT, IBM-PC-network-adapter:0.8Hz-120kHz+0dB-3dB
|Input sensitivity/impedance||Phono man month: 2.5mV / 47kohm|
MC: 170 microvolts/220 ohms
tuner, compact disk, Tape1, 2, DAT:150mV /, 47kohm
Power amp direct: 1V/22kohm
|S/N ratio||Phono MM:88dB(IHF’66)|
MC: 72dB (a 250-microvolt input, IHF’66)
tuner, compact disk, Tape1, 2, DAT: 104dB (IHF’66)
Power amp direct:115dB(IHF’66)
|Maximum permissible input||Phono MM:160mV|
|Tone control||bass:}10dB (50Hz)|
|Power source||AC100V, 50Hz/60Hz|
|Dimensions||Width 430x height 186x depth of 438mm|