Audio Database

Amplifier2
Commentary

This is an integrated amplifier with a focus on sound quality, with harmonic time alignment technology at the core.

The Harmonic Time Alignment Theory was developed by Steve Kalison of the Nakamichi US Research Center as a result of many years of research focusing on the characteristics of NFB itself. It directly addresses the timing of the fundamental sound and the distortion component and the action of NFB.
In Amplifier2, a newly developed amplifier circuit based on this theory is used in both the preamplifier and power amplifier sections. This circuit has a wide-band, low-gain open-loop design that keeps the amount of NFB in the audio band constant and suppresses the amount of NFB itself slightly. This circuit combines techniques that correctly adjust the phases of the fundamental sound and distortion components over the entire audio band.

The line amplifier section is composed of discrete elements so that high-quality sound devices can be installed.
As a result, high-quality parts which cannot be used in IC configuration can be used everywhere, and the frequency characteristics of the open-loop gain can be kept constant.
We also use a main volume driven by a motor drive, a motor drive rotary selector, and an electrolytic capacitor with an emphasis on sound quality.

A multi-regulated power supply system is employed to prevent interference between sections and stages surrounding the power supply.
The ground circuit also uses Nakamichi's original isolated ground system to reduce noise interference to the signal system.

Equipped with a high-gain equalizer amplifier with a transistor differential input.

Equipped with CD direct input, signal input from here jumps selector and balance volume, and simple signal transmission is possible by passing through dedicated 4-connected volume.

Equipped with tone control and muting circuit.

It comes with a remote control that can adjust volume, switch input, and operate Nakamichi CD player and deck.

The following are sold separately : signal converter RC-4 used for system remote connection between Amplifier series and remote control deck such as CR-70/CR-50/CR-40/CR-30/CR-20/DRAGON, SRC-2 used for system remote connection between second Casettedeck1/Casettedeck2/Nakamichi1000, and exclusive cable SRC-3 used for system remote connection between Nakamichi1000/1000II/700/700II and Amplifier series.

Model Rating
Type Integrated amplifier
Power Amplifier Unit
Rated output 50W + 50W (8 Ω, double-channel drive, 20 Hz to 20 kHz, 0.1% THD)
Power bandwidth 10 Hz to 50 kHz
Frequency characteristic 5 Hz ~ 80 kHz + 0 -3dB
S/N days (IHF A-WTD, input short) 105dB
Total harmonic distortion factor 0.1% or Less (8 Ω, Rated Output, 20 Hz to 20 kHz)
Maximum output current 18A peak (per one channel)
Preamplifier Section
Input Sensitivity / Impedance Phono MM : 2.5mV/47k Ω
Phono MC : 0.125mV/100 Ω
CD, Tuner, Tape, Aux : 150mV/20k Ω
Total harmonic distortion factor
(at 1 kHz, Rec out, 1 V output)
Phono MM : not more than 0.008%
Phono MC : not more than 0.01%
RIAA deviation Phono MM/MC : 30 Hz to 20 kHz ± 0.5 dB
Signal-to-noise ratio
IHF A-WTD, speaker out
Phono MM:82dB
Phono MC:70dB
Tone control Bass : ± 10 dB (20 Hz)
Treble : ± 10 dB (20 kHz)
<General>
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption Up to 370W
Power outlet Switched : 2 systems, up to 150W total
External dimensions Width 430x Height 125x Depth 360 mm
Weight Approx. 12.5 kg
Sold Separately Remote Signal Converter RC-4
System Remote Connecting Cable SRC-2 (¥ 1,200)
System Remote Connecting Cable SRC-3 (¥ 1,500)
Attachment : Remote Control Unit Amplifier2 Remote Control
Method Infrared pulse type
Pwer DC3V(1.5Vx2)
External dimensions 64 mm wide x 18 mm high x 176 mm deep
Weight Approx. 140g (Including Battery)