Description
Luxman C-120A Series Stereo Duo-Beta Preamplifier Trade-In
- Fully Inspected & Tested
- Wood cabinet touched up and oiled (some veneer blemishes)
- New Power Cord
The main amplifier section consists of a double-stage differential-amplifier circuit, all-stage direct connection pure complimentary service OCL system, and triple push-pull output-circuit.
The output stage employs a triple push-pull configuration using six power transistors per channel with high fT (high-cut-off frequency) and gain as much as possible. Using the excellent linearity of the hfe-Ic characteristic of each transistor, stable operation at a low distortion rate from high output to low output is achieved.
An emitter-follower circuit is installed between the pre-drive stage of class A operation and the output stage of class B operation. This circuit prevents distortion characteristics from deteriorating due to impedance changes caused by the speaker load reaching the pre-drive stage, and improves the load condition in the high-frequency range of the pre-drive stage. In addition to providing constant current drive at important points, a transistor with high fT and low Cob (collector output capacity) is adopted. This enables stable low-distortion drive over the entire band with only light phase correction.
The power supply consists of four large-capacity capacitors (15,000 μ F) combined with two high-efficiency and low-leakage toroidal transformers. In addition, the output stage of class B operation is divided into left and right channels, and the power supply to the pre-drive stage of class A operation is supplied with a constant voltage. This realizes an ideal power supply system in which both channels operate simultaneously and one channel operate at the same output.
It also has a circuit to control the rush current when the power switch is turned on.
As protection circuits, a DC drift detection circuit for speaker protection, an abnormal current detection circuit for amplifier protection, a heat sink abnormal temperature detection circuit, and a fuse blown detection circuit for power transistor monitoring are mounted.
The input circuit uses a 1-dB step precision level detent volume similar to a high-grade attenuator for level setting.
It is also designed to provide electrical isolation between the control amplifier and the main amplifier circuit by providing a constant-current driven emitter-follower stage so that both operate in the best condition.
It is equipped with a large VU meter with average level indication and LED peak indicator with peak value indication.
It is also equipped with an output display sensitivity switching function of 0 db ~ -10dB and an output display OFF switch.
Features & Specifications:
Power output: 180 watts per channel into 8Ω (stereo)
Frequency response: 3Hz to 100kHz.
Total harmonic distortion: 0.05%
Input sensitivity: 1V.
Signal to noise ratio: 108dB.
Dimensions: 485 x 390 x 175mm.
Weight: 28kg.
Warranty
90 Day acX Warranty
