This pre-main amplifier achieves high sound quality by using an excellent circuit structure và carefully selected high-precision parts.The EQ consists of a first stage differential, a 3-stage direct connection, a final stage class A operation pure complimentary service SEPP & two positive and negative power nguồn supplies.
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In addition, the NFB device for obtaining EQ deviation uses carefully selected elements such as a nichrome evaporated metal film resistor with a resistance error of ± 1% và a temperature characteristic of ± 50ppm/c, & a styrene capacitor with a capacitance error of ± 2%. These elements provide excellent characteristics.A voltage of ± 30 V is applied to lớn this circuit. The maximum output of the equalizer amplifier is 18 V, the maximum allowable input đầu vào is 300 mV, and the sensitivity is 2.5 mV. This circuit has a large dynamic margin.In order to maximize the performance of many cartridges, both Phono1 & 2 are equipped with cartridge load switching switches that can independently select 4 types of load resistance and 4 types of load capacity.The flat amplifier in the control section consists of a first stage differential and a two stage direct-coupled circuit.Xem thêm: Top 19 Những Câu Nói Hay Về Lí Luận Văn Học Về Văn Xuôi, 100 Nhận Định Lí Luận Văn Học Về Văn Xuôi
By using differential amplification in the first stage, the operating point is selected in the linear region of the transistor to lớn reduce distortion.Both Bass và Treble use a twin-tone control with main and sub two variable positions. Variable uses a switch-type volume in 2 dB steps.A 32-step attenuator is used for the volume, and the gang error between the left and right channels is as small as 0.5 dB or less, and the error with the indicated value on the panel surface is within ± 0.5 dB.In addition, it is equipped with a muting lever of -20dB, & delicate volume adjustment is possible by combination.The power amplifier circuit is composed of ± 2 nguồn supply, 2 stage differential amplifier current mirror circuit and final stage parallel push-pull pure complimentary service OCL circuit.The input is a differential amplifier to lớn suppress voltage fluctuations due lớn changes in external temperature and to reduce distortion. The pre-driver stage is made to be a constant current by the current mirror circuit to increase bare characteristics and to reduce distortion with sufficient NFB, & at the same time, even order harmonic distortion is suppressed. The NFB loop from the đầu ra stage has a large time constant so that the circuit operation is similar to that of a DC amplifier and phase shift is reduced. The đầu ra stage is a parallel push-pull lớn stably take out a large output.The radiator uses an efficient chimney style lớn enhance thermal stability.The power nguồn supply section uses two power transformers with independent left and right channels, và consists of two heavyweight transformers & a 12,000 μ Fx4 large-capacity capacitor.With this two power nguồn transformer configuration, channel crosstalk is improved by eliminating channel interference at the power nguồn supply.The protection circuit consists of a highly reliable twin-contact nguồn relay và a fast response electronic circuit.It also eliminates power-on clicks.It is equipped with auxiliary functions such as pre-power separation terminal, 2-system tape monitor, tone on-off switch, loudness contour, low-cut (subsonic) & high-cut filter.
Model Rating
| Type | Stereo pre-main amplifier | |
| Power Amplifier Unit | ||
| Circuit system | 2-stage all-stage direct-coupled parallel PP pure complimentary service OCL | |
| Effective power(Both channel drive, đôi mươi Hz to 20 kHz) | 100W + 100W (4 Ω)80W + 80W (8 Ω) | |
| Harmonic distortion factor (20 Hz to 20 kHz) | 0.05% (at effective output)0.01% (8 Ω at 40W output)0.01% (8 Ω at 1W output) | |
| Cross modulation distortion factor(50Hz:7kHz=4:1) | 0.05% (at effective output)0.01% (8 Ω at 40W output)0.01% (8 Ω at 1W output) | |
| Output Bandwidth (IHF, both channel drives) | 5 Hz khổng lồ 45 kHz (Distortion Factor 0.05%) | |
| Frequency characteristic | 5 Hz to 100 kHz + 0 -1dB | |
| Input Sensitivity / Impedance | Power amp in : 1V/50k Ω | |
| Output terminal | Speaker A / B : 4 Ω ~ 16 ΩSpeaker A + B : 8 Ω ~ 16 ΩHeadphone : 4 Ω ~ 16 Ω | |
| Damping factor | 30 (20 Hz ~ trăng tròn kHz, 8 Ω) | |
| S/N | 110 dB (IHF, A-network, short circuit) | |
| Preamplifier Section | ||
| Circuit system | Equalizer amplifier : First stage differential 3-stage direct connection Class A SEPPTone control part : first stage differential 2-stage direct connection flat amplifier, NFB type twin tone | |
| Input Sensitivity / Impedance | Phono1, 2 : 2.5mV/10k Ω, 25k Ω, 50k Ω, 100k ΩCartridge Load Capacity : 100 pf, 200 pf, 300 pf, 400 pf (for both Phono1 & 2)Tuner, Aux, Tape play1, 2 : 150mV/50k Ω | |
| Phono maximum allowable input | Phono1, 2 : 300 mV (1 kHz, harmonic distortion rate 0.05%) | |
| Output màn chơi / Impedance | Tape Rec1, 2 : 150 mvPre out : 1V/2k Ω, 10V/2k Ω (max) | |
| Harmonic distortion factor (20 Hz to trăng tròn kHz) | 0.01% (1 V Output)0.1% (10 v Output) | |
| Frequency characteristic | Phono : đôi mươi Hz to trăng tròn kHz ± 0.2 dBTuner, Aux, & Tape play : 5 hz lớn 50 khz + 0 lớn 1 db | |
| Tone control | Bass | Sub : ± 6 dB (50 Hz)Main : ± 8 dB (100 Hz) |
| Treble | Sub : ± 6 dB (20 kHz)Main : ± 8 dB (10 kHz) |
