ONKYO Integra A-733NII/130
¥ 89,800 (released in 1975)
Commentary
The NII series pre-main amplifier has improved sound quality by analyzing the dynamic characteristics of all stages of the amplifier and enhancing the power supply and ground line.
In order to improve the separation of the pre-main amplifier in the NII series, the correlation between the vector analysis of the separation characteristics and the audibility is thoroughly clarified. The NII series is designed so that the absolute value of the separation is kept to a value that is sufficiently negligible, and the phase is around which the most natural audibility can be obtained.
The power supply section uses a 1.6 mm thick bare earth line made of pure copper and a 5.5 mm copper wire equivalent to five 50-core wires, and two 15,000 μ F electrolytic capacitors dedicated to the power supply with low earth impedance.
As a result, the rise and fall of the middle and low frequencies, which are important for the excitement of the basic rhythm of music, are improved.
The power amplifier circuit employs a single-stage differential constant-current drive OTL circuit that has been developed to reduce the rise characteristics and distortion, especially to improve linearity.
Linearity (h), especially for the driver stageFEAnd high frequency characteristics (CobF)TThe power band width characteristic, which greatly affects audibility, has been extended up to 100 kHz.
The tone amplifier circuit is an operational amplifier type circuit with a differential 1-stage 3-chip configuration.
By selecting an optimum time constant, ensuring a dynamic range in an open loop, and improving the SN ratio, we have achieved a low-distortion design with excellent response characteristics regardless of tone ON / OFF.
The equalizer circuit uses an operational amplifier with a single 3-chip configuration at the final stage.
The power supply of the preamplifier uses a feedback-stabilized ± 2-conductor Minamoto no Sadamu voltage circuit with a fluctuation rate of 1.7%. This circuit is carefully designed to avoid the influence of power supply fluctuations.
The volume control and tone control use a precision trimming Attenuator volume with an interlocking error of ± 0.5 dB.
The volume can be freely set in the middle position with 32 contacts, and the tone can be adjusted in 10 2 db steps.
.JPG)
Model Rating
| Type | Pre-main amplifier | ||||
| Power Amplifier Unit | |||||
| Rated Output (Both channel drive) |
|
||||
| Dynamic Power (1 kHz, 8 Ω) | 200W | ||||
| Total harmonic distortion rate (1 kHz) | 0.05% or Less (at Rated Output) 0.03% or less (at 10W output) 0.03% or less (at 0.5W output) |
||||
| Intermodulation Distortion Factor (SMPTE, 70 hz : 7 khz = 4 : 1) | 0.05% or Less (at Rated Output) | ||||
| Power Band With (IHF-3dB, THD 0.3%) | 10 Hz to 100 kHz | ||||
| Signal-to-noise ratio (IHF A network, input shunt) | 110 dB or more | ||||
| Damping factor (DC ~ 20 kHz) | 8 Ω : 80 4 Ω : 40 |
||||
| Load impedance | 4 Ω ~ 16 Ω | ||||
| Input impedance (10 Hz to 50 kHz) | 100k Ω | ||||
| Gain | 26.5dB | ||||
| Rated input voltage (Main-In) | 1V | ||||
| Input-output polarity | Inphase | ||||
| Output terminal | Speaker : A, B, A + B switching Headphone jack |
||||
| Preamplifier Section | |||||
| Input Sensitivity / Impedance | Phono1 : 1.2 mV, 2.4 mV, 4.8mV/50k Ω Phono2 : 1.2 mV, 2.4 mV, 4.8mV/50k Ω Tuner, AUX1, 2, Tape Play1, 2 : 100mV/50k Ω |
||||
| Total Harmonic Distortion Factor (1 v, 1 khz) | Not more than 0.03% | ||||
| Intermodulation Distortion Factor (1 v, SMPTE, 70 hz : 7 khz = 4 : 1) | Not more than 0.05% | ||||
| RIAA deviation (Phono1, 2, 30 Hz-15 kHz) | ± 0.5 dB or less | ||||
| Phono Maximum Allowable Input (1kHz/10kHz (RMS)) | 250mV/1100mV (Sensitivity 2.4 mv, THD 0.1%) | ||||
| S/N (IHF A network) | Phono1, 2 : 75 dB or more Tuner, AUX1, 2, Tape Play1, 2 : 90 dB or higher |
||||
| Output voltage | Pre Out (100k Ω load) : Rated 1 v, maximum 4 v Tape Rec1, 2 : Rated at 100 mv |
||||
| Output impedance | Pre Out : 2.7k Ω Tape Rec1, 2 : 12k Ω |
||||
| Tone control | Treble at 2 kHz turnover : ± 10 dB at 10 kHz Bass at a turnover of 400 Hz : ± 10 dB at 100 Hz |
||||
| Turnover frequency | Treble : 2 khz, 8 khz, Defeat Bass : 400 Hz, 125 Hz, Defeat |
||||
| Loudness (at volume -30dB) | +5dB(70Hz) | ||||
| Filter | High-Filter : 5 kHz, 20 kHz, 6dB/oct. Low-Filter : 10 Hz, 30 Hz, 6dB/oct. |
||||
| Muting | -20dB | ||||
| Input-output polarity | EQ Amp : Same Phase Tone + Buffer Amp : in-phase |
||||
| Transient killer action | At SW-On : approximately 4 seconds At SW-Off : Start from 0.5 seconds |
||||
| <General> | |||||
| Semiconductor used | Transistor : 43 Diode : 38 pcs |
||||
| Pwer | 100 VAC, 50Hz/60Hz | ||||
| AC Output | Switched : 2 systems, 200 VA Unswitched : 1 line, 200 VA |
||||
| Power consumption | Electrical Appliance and Material Control Law Standard : 160W Maximum power consumption : 470W |
||||
| External dimensions | Width 467x Height 161x Depth 384 mm | ||||
| Weight | 13.8kg | ||||