Panasonic SU-V900: Integrated amplifier

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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.

FormIntegrated amplifier
<Power amplifier part>
Effective output100W+100W (20Hz – 20kHz, T.H.D 0.007%, 6ohms)
THD0.003% (20Hz – 20kHz-3dB, 8ohms)
Dumping factor110 (8ohms)
55 (4ohms)
<Preamplifier part>
Frequency characteristicPhono:RIAA standard curve}0.2dB
tuner, compact disk, Tape1, 2, DAT, IBM-PC-network-adapter:0.8Hz-120kHz+0dB-3dB
Input sensitivity/impedancePhono 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 ratioPhono 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 inputPhono MM:160mV
Tone controlbass:}10dB (50Hz)
treble:}10dB (20kHz)
Power sourceAC100V, 50Hz/60Hz
Power consumption235W
DimensionsWidth 430x height 186x depth of 438mm