Audio Database

Image of Integra A-722NII/160
Commentary

This is the top-of-the-line model of the Integra NII series. It was developed with the aim of thoroughly improving the rise characteristics of the middle and low sound range and accurately reproducing the presence and sense of orientation by vector analysis of the separation characteristics.

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 18,000 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 composed of four single-stage differential amplifiers for one stage and 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.
Volume can be freely set in the middle position with 43 contacts, and tone can be adjusted in 10 2 dB steps.

Model Rating
Type Pre-main amplifier
Power Amplifier Unit
Rated Output (Both channel drive)
1kHz: 80W + 80W (8 Ω)
90W + 90W (4 Ω)
20 Hz to 20 kHz : 75W + 75W (8 Ω)
Dynamic Power (1 kHz, 8 Ω) 240W
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 28dB
Rated input voltage (Main-In) 1V
Input-output polarity Inphase
Output terminal Speaker : A, B, C, A + B
Headphone jack
Preamplifier Section
Input Sensitivity / Impedance Phono1 : 1.2 mV, 2.4 mV, 4.8mV/100k Ω, 50k Ω, 30k 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 (SMPTE, 70 hz : 7 khz = 4 : 1) 0.05% or Less (1 V)
RIAA deviation (Phono1, 2, 30 Hz-15 kHz) ± 0.2 dB or Less
Phono Maximum Allowable Input (1kHz/10kHz (RMS)) 330mV/1540mV (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) + 5 dB at 70 Hz, + 3 dB at 10 kHz
Two step switching of Low and Low + High
Filter High-Filter : 5 kHz, 20 kHz, 6dB/oct.
Low-Filter : 10 Hz, 30 Hz, 12dB/oct.
Muting -10dB/-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 : 49
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 : 200W
Maximum power consumption : 620W
External dimensions Width 467x Height 161x Depth 384 mm
Weight 14.3kg