Audio Database

Image of the Integra H-1E
Commentary

An MC head amplifier that improves the S/N ratio by taking advantage of the frequency characteristics and distortion factor characteristic of a head amplifier for electronic circuits.

In order to improve the S/N ratio, a source feedback amplifier circuit is adopted.
The equivalent noise resistance of the input stage of a source-feedback amplifier circuit is 1 / 2 of that of a general differential amplifier often used in the first stage because of its excellent DC performance. Therefore, the S/N ratio can be improved in a head amplifier that handles minute level signals.
In addition, by using this circuit, the slew rate is increased and wide-band reproduction is possible.

The newly developed SEPP (Single Ended Push-Pull) power supply with excellent noise performance is used to take advantage of the low noise characteristics of the head amplifier.
The push-pull operation improves the linearity of impedance against output current fluctuation and realizes high-speed response.
In addition, the response to the increasing and decreasing directions of the current becomes symmetrical, and the fluctuation of the power supply voltage can be reduced.

The equalizer amplifier uses the NF type, which has a proven track record as a separate amplifier, and has acquired excellent characteristics by using carefully selected high-precision parts.
In addition, a DC servo circuit has been incorporated and coupling capacitors have been eliminated to improve sound purity.

The power supply unit is a twin power supply consisting of a LASER transformer with ultra-low leakage flux characteristics that suppresses leakage so that the flux leaked from the transformer does not pollute the music signal. The transformer is installed separately for the head amplifier and for the equalizer amplifier.
In addition, the condenser is equipped with a blue condenser (development number 923), which was developed over three years to solve the difficult problem of achieving both energy sensitivity and high resolution.

A 9 mm thick all-aluminum monocoque chassis is used for the front panel.
By providing many ribs on the inner and outer surfaces, the rigidity of the chassis is improved and unwanted resonance is reduced. In addition, DuPont Corian, which combines rigidity and vibration control, is used for the insulator that supports the chassis.

To achieve high sound quality, we have adopted a high-sound film condenser, carbon resistance, and a printed circuit board with a copper foil thickness of 70 μ m.
The PIN terminal is made of a highly rigid brass ground gold plated terminal. The rear panel of this terminal is fixed rigidly with two point connections for one pair of left and right terminals. The distance between the left and right terminals is 18 mm, enabling the use of very thick PIN plugs.

The muting circuit is a soft muting circuit that reduces unpleasant noise during operation, and uses a shunt type that does not affect sound quality.

Model Rating
Type Phono preamplifier
Input Sensitivity / Impedance MC (Hi) : 150 μ V/100 Ω
MC (Lo) : 150 μ V/50 Ω
MM : 3.0mV/47k Ω
Allowable input
(1 kHz, 0.05% THD)
MC:6.0mV
MM:120mV
Rated Output / Impedance 300mV/200 Ω
Maximum power output 12V
Total harmonic distortion factor
(20 Hz to 20 kHz, 3 V Output)
MC : not more than 0.003%
MM : not more than 0.0008%
S/N ratio (A-weighted) MC : 80 dB (0.5 mV input / input short)
MM : 88 dB (5.0 mV input / input short)
RIAA deviation ± 0.15 dB (20 Hz to 20 kHz)
Output muting attenuation 65 dB or more (Soft Muting)
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law) 18W
External dimensions Width 435x Height 85x Depth 359 mm
Weight 6.6kg