KENWOOD KA-4050R

Commentary

Pre-main amplifier using MOS-FET.

MOS-FET is adopted in the driver stage of the power part.
Since the MOS-FET has a higher input resistance than a conventional bipolar transistor, it is possible to break the electrical coupling of each stage. It also has excellent high-frequency characteristics and linearity of small-signal amplification.

Super C, which is used in the high-grade amplifier L-A1, compared to the first stage amplifier₄It is equipped with a high-precision differential amplifier circuit which is based on the same concept as the above circuit, so that noise from the power supply circuit is not mixed, and in-phase component noise is reduced and S/N is improved.
The first stage amplifier is stage amplifier is placed close to the volume to prevent the influence of the output stage of the power section and power supply circuit.

A pure signal ground line is used to prevent noise from entering through the power supply ground line.
The power supply ground line and the signal ground line do not overlap inside the amplifier, and the ground line is concentrated at one point of the speaker terminal. Only pure signal flows through the signal main ground line, enabling more pure amplification.

To prevent the aging of the rotary switch type input selector, an inert gas-filled relay switch is used in the input selector.
This reduces contact wear, which is an advantage of the relay, and eliminates signal transmission loss due to oxidation of the contact.

It is equipped with a source direct circuit and a phono equalizer amplifier with MM/MC gain switching.
The speaker terminal is a large speaker terminal compatible with banana terminal.

A 27 key system remote control is included.

Model Rating

Type	Integrated amplifier
Rated Output (20 Hz to 20 kHz, Both Channel Operation)	70W + 70W (6 Ω, THD 0.06%) 60W + 60W (8 Ω, THD 0.06%)
Dynamic Power	120W + 120W (4 Ω) 90W + 90W (8 Ω)
Total Harmonic Distortion Factor (CD, 8 Ω, 60W)	0.06% (20 Hz to 20 kHz) 0.02%(1kHz)
Frequency characteristic	Overall (Line → Speaker) : 5 Hz ~ 100 kHz + 0 -3dB
Signal-to-noise ratio	Phono MM: 79dB(EIAJ) 87 dB (input short) Phono MC: 74dB(EIAJ) 67 dB (input short) DAT, CD, Tuner, AUX, Tape Play : 80dB(EIAJ) 104 dB (input short)
Input sensitivity / impedance (at rated output)	Phono MM : 2.5mV/47k Ω Phono MC : 0.2mV/100 Ω DAT, CD, Tuner, AUX, Tape Play : 200mV/47k Ω
Phono maximum allowable input (Phono → Tape Rec, 1 kHz, THD 0.05%)	MM:120mV MC:10mV
Output Level / Impedance	Tape Rec : 200mV/1k Ω
Power supply voltage	100 VAC, 50Hz/60Hz
Rated power consumption (Electrical Appliance and Material Control Law)	115W
AC outlet	Power switch interlock : Route 3, total 200W
Maximum external dimensions	Width 440x Height 136.5x Depth 345 mm
Weight	8.5kg